nq2.htm



 
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY
 
Investment Company Act file number 811-6623
 
Nuveen California Select Tax-Free Income Portfolio
(Exact name of registrant as specified in charter)
 
Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)
 

Kevin J. McCarthy
Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)
 
Registrant's telephone number, including area code:         312-917-7700        
 
Date of fiscal year end:            3/31          
 
Date of reporting period:         12/31/12         
 
Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.
 
A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

 
 
 

 
 
Item 1. Schedule of Investments
 

 
           
   
Portfolio of Investments (Unaudited) 
     
   
Nuveen California Select Tax-Free Income Portfolio (NXC) 
     
   
December 31, 2012 
     
 
 
Principal 
   
Optional Call 
   
Amount (000) 
 
Description (1) 
Provisions (2) 
Ratings (3) 
Value 
   
Consumer Staples – 4.8% 
     
$ 140 
 
California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Bonds, Sonoma 
6/15 at 100.00 
BB+ 
$    135,846 
   
County Tobacco Securitization Corporation, Series 2005, 4.250%, 6/01/21 
     
940 
 
California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Revenue 
3/13 at 100.00 
A3 
942,651 
   
Bonds, Fresno County Tobacco Funding Corporation, Series 2002, 5.625%, 6/01/23 
     
   
Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed 
     
   
Bonds, Series 2007A-1: 
     
1,065 
 
5.750%, 6/01/47 
6/17 at 100.00 
BB– 
1,012,293 
1,885 
 
5.125%, 6/01/47 
6/17 at 100.00 
BB– 
1,631,336 
1,095 
 
Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed 
6/22 at 100.00 
BB– 
994,753 
   
Bonds, Series 2007A-2, 5.300%, 6/01/37 
     
5,125 
 
Total Consumer Staples 
   
4,716,879 
   
Education and Civic Organizations – 3.9% 
     
3,000 
 
California Educational Facilities Authority, Revenue Bonds, Santa Clara University, Series 2008A, 
4/18 at 100.00 
Aa3 
3,422,758 
   
5.625%, 4/01/37 
     
45 
 
California Educational Facilities Authority, Revenue Bonds, University of Redlands, Series 2005A, 
10/15 at 100.00 
A3 
46,879 
   
5.000%, 10/01/35 
     
   
California Educational Facilities Authority, Revenue Bonds, University of the Pacific, Series 2006: 
     
35 
 
5.000%, 11/01/21 
11/15 at 100.00 
A2 
37,890 
45 
 
5.000%, 11/01/25 
11/15 at 100.00 
A2 
48,249 
250 
 
California Statewide Communitities Development Authority, School Facility Revenue Bonds, 
7/21 at 100.00 
BBB 
283,910 
   
Alliance College-Ready Public Schools, Series 2011A, 7.000%, 7/01/46 
     
3,375 
 
Total Education and Civic Organizations 
   
3,839,686 
   
Health Care – 12.6% 
     
235 
 
California Health Facilities Financing Authority, Revenue Bonds, Rady Children’s Hospital – 
8/21 at 100.00 
A+ 
256,322 
   
San Diego, Series 2011, 5.250%, 8/15/41 
     
2,550 
 
California Health Facilities Financing Authority, Revenue Bonds, Sutter Health, Series 2007A, 
11/16 at 100.00 
AA– 
2,785,799 
   
5.250%, 11/15/46 (UB) 
     
1,500 
 
California Statewide Community Development Authority, Insured Mortgage Hospital Revenue 
5/13 at 100.00 
A– 
1,502,295 
   
Bonds, Mission Community Hospital, Series 2001, 5.375%, 11/01/26 
     
425 
 
California Statewide Community Development Authority, Revenue Bonds, Childrens Hospital of 
8/17 at 100.00 
BBB+ 
444,125 
   
Los Angeles, Series 2007, 5.000%, 8/15/47 
     
545 
 
California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanente 
8/16 at 100.00 
A+ 
600,361 
   
System, Series 2001C, 5.250%, 8/01/31 
     
2,000 
 
California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanente 
4/17 at 100.00 
A+ 
2,151,000 
   
System, Series 2007A, 4.750%, 4/01/33 
     
1,000 
 
California Statewide Community Development Authority, Revenue Bonds, Sutter Health, Series 
11/15 at 100.00 
AA– 
1,076,660 
   
2005A, 5.000%, 11/15/43 
     
540 
 
Loma Linda, California, Hospital Revenue Bonds, Loma Linda University Medical Center, Series 
12/17 at 100.00 
BBB 
630,083 
   
2008A, 8.250%, 12/01/38 
     
1,100 
 
Palomar Pomerado Health Care District, California, Certificates of Participation, Series 2010, 
11/20 at 100.00 
Baa3 
1,187,120 
   
6.000%, 11/01/41 
     
670 
 
San Buenaventura, California, Revenue Bonds, Community Memorial Health System, Series 2011, 
12/21 at 100.00 
BB 
826,814 
   
7.500%, 12/01/41 
     
800 
 
Upland, California, Certificates of Participation, San Antonio Community Hospital, Series 2011, 
1/21 at 100.00 
A
940,264 
   
6.500%, 1/01/41 
     
11,365 
 
Total Health Care 
   
12,400,843 
   
Housing/Multifamily – 0.8% 
     
375 
 
California Municipal Finance Authority, Mobile Home Park Revenue Bonds, Caritas Projects Series 
8/20 at 100.00 
BBB 
415,928 
   
2010A, 6.400%, 8/15/45 
     
395 
 
California Municipal Finance Authority, Mobile Home Park Revenue Bonds, Caritas Projects Series 
8/22 at 100.00 
BBB 
419,842 
   
2012A, 5.500%, 8/15/47 
     
770 
 
Total Housing/Multifamily 
   
835,770 
   
Housing/Single Family – 0.1% 
     
55 
 
California Housing Finance Agency, Home Mortgage Revenue Bonds, Series 2006H, 5.750%, 
2/16 at 100.00 
BBB 
57,548 
   
8/01/30 – FGIC Insured (Alternative Minimum Tax) 
     
   
Industrials – 1.2% 
     
1,015 
 
California Pollution Control Financing Authority, Solid Waste Disposal Revenue Bonds, Republic 
No Opt. Call 
BBB 
1,147,326 
   
Services Inc., Series 2002C, 5.250%, 6/01/23 (Mandatory put 12/01/17) (Alternative 
     
   
Minimum Tax) 
     
   
Tax Obligation/General – 39.4% 
     
750 
 
California State, General Obligation Bonds, Series 2004, 5.000%, 2/01/23 
2/14 at 100.00 
A1 
785,318 
1,650 
 
California State, General Obligation Bonds, Various Purpose Series 2009, 5.500%, 11/01/39 
11/19 at 100.00 
A1 
1,916,904 
1,965 
 
California State, General Obligation Bonds, Various Purpose Series 2011, 5.000%, 10/01/41 
10/21 at 100.00 
A1 
2,208,247 
2,000 
 
California State, General Obligation Bonds, Various Purpose Series 2012, 5.250%, 4/01/35 
4/22 at 100.00 
A1 
2,332,040 
6,225 
 
Escondido Union High School District, San Diego County, California, General Obligation Refunding 
No Opt. Call 
Aa2 
1,994,428 
   
Bonds, Series 2009, 0.000%, 8/01/36 – AGM Insured 
     
   
Golden West Schools Financing Authority, California, General Obligation Revenue Refunding Bonds, 
     
   
School District Program, Series 1999A: 
     
4,650 
 
0.000%, 8/01/16 – NPFG Insured 
No Opt. Call 
BBB 
4,159,656 
1,750 
 
0.000%, 2/01/17 – NPFG Insured 
No Opt. Call 
BBB 
1,516,148 
2,375 
 
0.000%, 8/01/17 – NPFG Insured 
No Opt. Call 
BBB 
2,017,349 
2,345 
 
0.000%, 2/01/18 – NPFG Insured 
No Opt. Call 
BBB 
1,964,453 
   
Mountain View-Los Altos Union High School District, Santa Clara County, California, General 
     
   
Obligation Capital Appreciation Bonds, Series 1995C: 
     
1,015 
 
0.000%, 5/01/17 – NPFG Insured 
No Opt. Call 
Aa1 
956,110 
1,080 
 
0.000%, 5/01/18 – NPFG Insured 
No Opt. Call 
Aa1 
991,580 
5,500 
 
Poway Unified School District, San Diego County, California, School Facilities Improvement District 
No Opt. Call 
Aa2 
1,026,245 
   
2007-1 General Obligation Bonds, Series 2011A, 0.000%, 8/01/46 
     
100 
 
Roseville Joint Union High School District, Placer County, California, General Obligation Bonds, 
8/15 at 100.00 
AA 
108,955 
   
Series 2006B, 5.000%, 8/01/27 – FGIC Insured 
     
3,220 
 
Sacramento City Unified School District, Sacramento County, California, General Obligation Bonds, 
7/15 at 100.00 
AA– 
3,476,117 
   
Series 2005, 5.000%, 7/01/27 – NPFG Insured 
     
8,075 
 
San Bernardino Community College District, California, General Obligation Bonds, Election of 
No Opt. Call 
Aa2 
1,573,898 
   
2008 Series 2009B, 0.000%, 8/01/44 
     
1,500 
 
San Diego Unified School District, San Diego County, California, General Obligation Bonds, Series 
7/13 at 101.00 
Aa2 
1,550,235 
   
2003E, 5.250%, 7/01/24 – AGM Insured 
     
26,655 
 
Southwestern Community College District, San Diego County, California, General Obligation Bonds, 
No Opt. Call 
Aa2 
4,907,184 
   
Election of 2008, Series 2011C, 0.000%, 8/01/46 
     
2,565 
 
Sunnyvale School District, Santa Clara County, California, General Obligation Bonds, Series 2005A, 
9/15 at 100.00 
AA 
2,815,395 
   
5.000%, 9/01/26 – AGM Insured 
     
4,250 
 
West Hills Community College District, California, General Obligation Bonds, School Facilities 
8/31 at 100.00 
AA– 
2,443,495 
   
Improvement District 3, 2008 Election Series 2011, 0.000%, 8/01/38 – AGM Insured 
     
77,670 
 
Total Tax Obligation/General 
   
38,743,757 
   
Tax Obligation/Limited – 24.8% 
     
1,000 
 
Bell Community Redevelopment Agency, California, Tax Allocation Bonds, Bell Project Area, Series 
10/13 at 100.00 
N/R 
948,350 
   
2003, 5.625%, 10/01/33 – RAAI Insured 
     
2,650 
 
California State Public Works Board, Lease Revenue Bonds, Department of Corrections, Calipatria 
No Opt. Call 
A2 
2,972,903 
   
State Prison, Series 1991A, 6.500%, 9/01/17 – NPFG Insured 
     
1,000 
 
California State Public Works Board, Lease Revenue Bonds, Department of Mental Health, Coalinga 
6/14 at 100.00 
A2 
1,056,810 
   
State Hospital, Series 2004A, 5.500%, 6/01/23 
     
1,500 
 
California State Public Works Board, Lease Revenue Bonds, Various Capital Projects, Series 2009-I, 
11/19 at 100.00 
A2 
1,805,985 
   
6.375%, 11/01/34 
     
120 
 
Capistrano Unified School District, Orange County, California, Special Tax Bonds, Community 
9/15 at 100.00 
BBB 
124,044 
   
Facilities District, Series 2005, 5.000%, 9/01/24 – FGIC Insured 
     
360 
 
Chino Redevelopment Agency, California, Merged Chino Redevelopment Project Area Tax Allocation 
9/16 at 101.00 
A– 
365,285 
   
Bonds, Series 2006, 5.000%, 9/01/38 – AMBAC Insured 
     
2,000 
 
Escondido Joint Powers Financing Authority, California, Lease Revenue Bonds, Water System 
3/22 at 100.00 
AA– 
2,237,580 
   
Financing, Series 2012, 5.000%, 9/01/41 
     
1,000 
 
Fontana Public Financing Authority, California, Tax Allocation Revenue Bonds, North Fontana 
10/15 at 100.00 
A
1,026,650 
   
Redevelopment Project, Series 2005A, 5.000%, 10/01/32 – AMBAC Insured 
     
270 
 
Fontana Redevelopment Agency, California, Jurupa Hills Redevelopment Project, Tax Allocation 
4/13 at 100.00 
A– 
270,953 
   
Refunding Bonds, 1997 Series A, 5.500%, 10/01/27 
     
250 
 
Inglewood Redevelopment Agency, California, Tax Allocation Bonds, Merged Redevelopment 
5/17 at 100.00 
BBB+ 
257,635 
   
Project, Subordinate Lien Series 2007A-1, 5.000%, 5/01/23 – AMBAC Insured 
     
   
Irvine, California, Unified School District, Community Facilities District Special Tax Bonds, 
     
   
Series 2006A: 
     
55 
 
5.000%, 9/01/26 
9/16 at 100.00 
N/R 
56,725 
130 
 
5.125%, 9/01/36 
9/16 at 100.00 
N/R 
132,798 
215 
 
Los Angeles Community Redevelopment Agency, California, Lease Revenue Bonds, Manchester 
9/15 at 100.00 
A1 
224,219 
   
Social Services Project, Series 2005, 5.000%, 9/01/37 – AMBAC Insured 
     
135 
 
National City Community Development Commission, California, Tax Allocation Bonds, National 
8/21 at 100.00 
A– 
168,294 
   
City Redevelopment Project, Series 2011, 6.500%, 8/01/24 
     
280 
 
Norco Redevelopment Agency, California, Tax Allocation Bonds, Project Area 1, Refunding, School 
3/14 at 100.00 
N/R 
280,924 
   
District Pass-Through, Series 2004, 5.000%, 3/01/32 – RAAI Insured 
     
50 
 
Novato Redevelopment Agency, California, Tax Allocation Bonds, Hamilton Field Redevelopment 
9/21 at 100.00 
BBB+ 
58,505 
   
Project, Series 2011, 6.750%, 9/01/40 
     
1,300 
 
Orange County, California, Special Tax Bonds, Community Facilities District 03-1 of Ladera Ranch, 
8/13 at 100.00 
N/R 
1,310,036 
   
Series 2004A, 5.625%, 8/15/34 
     
   
Perris Union High School District Financing Authority, Riverside County, California, Revenue Bonds, 
     
   
Series 2011: 
     
50 
 
6.000%, 9/01/33 
3/13 at 103.00 
N/R 
51,587 
100 
 
6.125%, 9/01/41 
3/13 at 103.00 
N/R 
103,153 
415 
 
Pittsburg Redevelopment Agency, California, Tax Allocation Bonds, Los Medanos Community 
9/18 at 100.00 
BBB– 
454,126 
   
Development Project, Refunding Series 2008A, 6.500%, 9/01/28 
     
160 
 
Rancho Santa Fe CSD Financing Authority, California, Revenue Bonds, Superior Lien Series 2011A, 
9/21 at 100.00 
BBB+ 
184,250 
   
5.750%, 9/01/30 
     
105 
 
Rialto Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series 
9/15 at 100.00 
A– 
106,206 
   
2005A, 5.000%, 9/01/35 – SYNCORA GTY Insured 
     
30 
 
Riverside County Redevelopment Agency, California, Tax Allocation Bonds, Jurupa Valley Project 
10/21 at 100.00 
A– 
34,205 
   
Area, Series 2011B, 6.500%, 10/01/25 
     
130 
 
Roseville, California, Certificates of Participation, Public Facilities, Series 2003A, 5.000%, 8/01/25 – 
8/13 at 100.00 
AA– 
132,465 
   
AMBAC Insured 
     
605 
 
Sacramento City Financing Authority, California, Lease Revenue Refunding Bonds, Series 1993A, 
No Opt. Call 
A1 
700,136 
   
5.400%, 11/01/20 – NPFG Insured 
     
1,365 
 
San Diego County Regional Transportation Commission, California, Sales Tax Revenue Bonds, 
4/22 at 100.00 
AAA 
1,572,712 
   
Series 2012A, 5.000%, 4/01/42 
     
25 
 
San Francisco Redevelopment Finance Authority, California, Tax Allocation Revenue Bonds, Mission 
2/21 at 100.00 
A– 
29,641 
   
Bay North Redevelopment Project, Series 2011C, 6.750%, 8/01/41 
     
   
San Francisco Redevelopment Financing Authority, California, Tax Allocation Revenue Bonds, 
     
   
Mission Bay South Redevelopment Project, Series 2011D: 
     
25 
 
7.000%, 8/01/33 
2/21 at 100.00 
BBB 
29,332 
30 
 
7.000%, 8/01/41 
2/21 at 100.00 
BBB 
34,726 
615 
 
San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Area Redevelopment 
8/17 at 100.00 
BBB 
628,093 
   
Project, Series 2006C, 5.000%, 8/01/25 – NPFG Insured 
     
3,000 
 
San Mateo County Transit District, California, Sales Tax Revenue Bonds, Series 2005A, 5.000%, 
6/15 at 100.00 
AA 
3,307,350 
   
6/01/21 – NPFG Insured 
     
1,000 
 
Santa Clara County Board of Education, California, Certificates of Participation, Series 2002, 
4/13 at 100.00 
BBB 
1,002,130 
   
5.000%, 4/01/25 – NPFG Insured 
     
1,000 
 
Santa Clara Valley Transportation Authority, California, Sales Tax Revenue Bonds, Series 2007A, 
4/17 at 100.00 
AA+ 
1,118,150 
   
5.000%, 4/01/36 – AMBAC Insured 
     
40 
 
Signal Hill Redevelopment Agency, California, Project 1 Tax Allocation Bonds, Series 2011, 
4/21 at 100.00 
N/R 
44,577 
   
7.000%, 10/01/26 
     
1,000 
 
Travis Unified School District, Solano County, California, Certificates of Participation, Series 2006, 
9/16 at 100.00 
N/R 
1,023,790 
   
5.000%, 9/01/26 – FGIC Insured 
     
           
360 
 
Turlock Public Financing Authority, California, Tax Allocation Revenue Bonds, Series 2011, 
3/21 at 100.00 
BBB+ 
411,736 
   
7.500%, 9/01/39 
     
70 
 
Yorba Linda Redevelopment Agency, Orange County, California, Tax Allocation Revenue Bonds, 
9/21 at 100.00 
A– 
83,812 
   
Yorba Linda Redevelopment Project, Subordinate Lien Series 2011A, 6.500%, 9/01/32 
     
22,440 
 
Total Tax Obligation/Limited 
   
24,349,873 
   
Transportation – 1.2% 
     
1,150 
 
Foothill/Eastern Transportation Corridor Agency, California, Toll Road Revenue Bonds, Series 1995A, 
7/13 at 100.00 
BBB– 
1,149,920 
   
5.000%, 1/01/35 
     
   
U.S. Guaranteed – 1.6% (4) 
     
800 
 
California State, General Obligation Bonds, Series 2004, 5.125%, 2/01/27 (Pre-refunded 2/01/14) 
2/14 at 100.00 
AAA 
842,032 
500 
 
California Statewide Community Development Authority, Hospital Revenue Bonds, Monterey 
6/13 at 100.00 
AA– (4) 
510,310 
   
Peninsula Hospital, Series 2003B, 5.250%, 6/01/18 (Pre-refunded 6/01/13) – AGM Insured 
     
225 
 
San Mateo Union High School District, San Mateo County, California, Certificates of Participation, 
12/17 at 100.00 
AA– (4) 
270,932 
   
Phase 1, Series 2007A, 5.000%, 12/15/30 (Pre-refunded 12/15/17) – AMBAC Insured 
     
1,525 
 
Total U.S. Guaranteed 
   
1,623,274 
   
Utilities – 6.6% 
     
1,000 
 
Imperial Irrigation District, California, Electric System Revenue Bonds, Refunding Series 2011A, 
11/20 at 100.00 
AA– 
1,144,410 
   
5.500%, 11/01/41 
     
645 
 
Long Beach Bond Finance Authority, California, Natural Gas Purchase Revenue Bonds, Series 
No Opt. Call 
A
759,146 
   
2007A, 5.500%, 11/15/37 
     
200 
 
Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series 
7/13 at 100.00 
AA– 
204,718 
   
2003A-2, 5.000%, 7/01/21 – NPFG Insured 
     
7,600 
 
Merced Irrigation District, California, Certificates of Participation, Water and Hydroelectric 
9/16 at 64.56 
A
4,164,038 
   
Series 2008B, 0.000%, 9/01/23 
     
215 
 
Merced Irrigation District, California, Electric System Revenue Bonds, Series 2005, 5.125%, 
9/15 at 100.00 
N/R 
221,489 
   
9/01/31 – SYNCORA GTY Insured 
     
9,660 
 
Total Utilities 
   
6,493,801 
   
Water and Sewer – 3.9% 
     
   
California Pollution Control Financing Authority, Water Furnishing Revenue Bonds, Poseidon 
     
   
Resources Channelside Desalination Project, Series 2012: 
     
535 
 
5.000%, 7/01/37 (WI/DD, Settling 1/02/13) (Alternative Minimum Tax) 
No Opt. Call 
Baa3 
547,391 
1,000 
 
5.000%, 11/21/45 (Alternative Minimum Tax) 
No Opt. Call 
Baa3 
1,007,900 
150 
 
Healdsburg Public Financing Authority, California, Wastewater Revenue Bonds, Series 2006, 
4/16 at 100.00 
AA– 
163,460 
   
5.000%, 4/01/36 – NPFG Insured 
     
250 
 
Sacramento County Sanitation District Financing Authority, California, Revenue Bonds, Series 
6/16 at 100.00 
AA 
275,788 
   
2006, 5.000%, 12/01/31 – FGIC Insured 
     
825 
 
South Feather Water and Power Agency, California, Water Revenue Certificates of Participation, 
4/13 at 100.00 
A
828,944 
   
Solar Photovoltaic Project, Series 2003, 5.375%, 4/01/24 
     
1,000 
 
Woodbridge Irrigation District, California, Certificates of Participation, Water Systems Project, 
7/13 at 100.00 
A+ 
1,006,730 
   
Series 2003, 5.625%, 7/01/43 
     
3,760 
 
Total Water and Sewer 
   
3,830,213 
$ 137,910 
 
Total Investments (cost $87,686,304) – 100.9% 
   
99,188,890 
   
Floating Rate Obligations – (1.6)% 
   
(1,540,000) 
   
Other Assets Less Liabilities – 0.7% 
   
660,225 
   
Net Assets – 100% 
   
$ 98,309,115 
 
 
 
 
 

 
 
 
Fair Value Measurements
 
Fair value is defined as the price that the Fund would receive upon selling an investment or transferring a liability in an orderly transaction to an independent buyer in the principal or most advantageous market for the investment. A three-tier hierarchy is used to maximize the use of observable market data and minimize the use of unobservable inputs and to establish classification of fair value measurements for disclosure purposes. Observable inputs reflect the assumptions market participants would use in pricing the asset or liability. Observable inputs are based on market data obtained from sources independent of the reporting entity. Unobservable inputs reflect the reporting entity’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Unobservable inputs are based on the best information available in the circumstances. The following is a summary of the three-tiered hierarchy of valuation input levels.
 
 
Level 1 – Inputs are unadjusted and prices are determined using quoted prices in active markets for identical securities.
 
 
Level 2 – Prices are determined using other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.).
 
 
Level 3 – Prices are determined using significant unobservable inputs (including management’s assumptions in determining the fair value of investments).
 
 
The inputs or methodologies used for valuing securities are not an indication of the risks associated with investing in those securities. The following is a summary of the Fund’s fair value measurements as of the end of the reporting period:
 
 
Level 1 
Level 2 
Level 3 
Total 
Long-Term Investments: 
       
Municipal Bonds 
$ — 
$99,188,890 
$ — 
$99,188,890 
 
 
The Nuveen funds’ Board of Directors/Trustees is responsible for the valuation process and has delegated the oversight of the daily valuation process to the Adviser’s Valuation Committee. The Valuation Committee, pursuant to the valuation policies and procedures adopted by the Board of Directors/Trustees, is responsible for making fair value determinations, evaluating the effectiveness of the funds’ pricing policies, and reporting to the Board of Directors/Trustees. The Valuation Committee is aided in its efforts by the Adviser’s dedicated Securities Valuation Team, which is responsible for administering the daily valuation process and applying fair value methodologies as approved by the Valuation Committee. When determining the reliability of independent pricing services for investments owned by the funds, the Valuation Committee, among other things, conducts due diligence reviews of the pricing services and monitors the quality of security prices received through various testing reports conducted by the Securities Valuation Team.
 
 
The Valuation Committee will consider pricing methodologies it deems relevant and appropriate when making fair value determinations. Examples of possible methodologies include, but are not limited to, multiple of earnings; discount from market of a similar freely traded security; discounted cash-flow analysis; book value or a multiple thereof; risk premium/yield analysis; yield to maturity; and/or fundamental investment analysis. The Valuation Committee will also consider factors it deems relevant and appropriate in light of the facts and circumstances. Examples of possible factors include, but are not limited to, the type of security; the issuer’s financial statements; the purchase price of the security; the discount from market value of unrestricted securities of the same class at the time of purchase; analysts’ research and observations from financial institutions; information regarding any transactions or offers with respect to the security; the existence of merger proposals or tender offers affecting the security; the price and extent of public trading in similar securities of the issuer or comparable companies; and the existence of a shelf registration for restricted securities.
 
 
For each portfolio security that has been fair valued pursuant to the policies adopted by the Board of Directors/Trustees, the fair value price is compared against the last available and next available market quotations. The Valuation Committee reviews the results of such testing and fair valuation occurrences are reported to the Board of Directors/Trustees.
 
 
Income Tax Information
 
The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate securities reflected as financing transactions, if any. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset value of the Fund.
 
As of December 31, 2012, the cost of investments was $86,125,136.
 
Gross unrealized appreciation and gross unrealized depreciation of investments as of December 31, 2012, were as follows:
   
Gross unrealized: 
 
Appreciation 
$11,699,129 
Depreciation 
(180,387) 
Net unrealized appreciation (depreciation) of investments 
$11,518,742 
 
 
 
(1) 
All percentages shown in the Portfolio of Investments are based on net assets. 
 
(2) 
Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
   
There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
   
may be subject to periodic principal paydowns. 
 
(3) 
Ratings: Using the highest of Standard & Poor’s Group (“Standard & Poor’s”), Moody’s Investors Service, 
   
Inc. (“Moody’s”) or Fitch, Inc. (“Fitch”) rating. Ratings below BBB by Standard & Poor’s, Baa by Moody’s or 
   
BBB by Fitch are considered to be below investment grade. Holdings designated N/R are not rated by any 
   
of these national rating agencies. 
 
(4) 
Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities, 
   
which ensure the timely payment of principal and interest. Certain bonds backed by U.S. Government or 
   
agency securities are regarded as having an implied rating equal to the rating of such securities. 
 
N/R 
Not rated. 
 
WI/DD 
Purchased on a when-issued or delayed delivery basis. 
 
(UB) 
Underlying bond of an inverse floating rate trust reflected as a financing transaction. 
 
 

 
 
 

 
 
Item 2. Controls and Procedures.

a.  
The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
 
 
b.  
There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.
 
Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.

 
 
 

 
 
SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.
 
(Registrant)  Nuveen California Select Tax-Free Income Portfolio 
 
By (Signature and Title)     /s/ Kevin J. McCarthy                    
                                                   Kevin J. McCarthy
                                                   Vice President and Secretary
 
Date:         March 1, 2013        
 
Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.
 
By (Signature and Title)     /s/ Gifford R. Zimmerman                    
                                                    Gifford R. Zimmerman
                                                  Chief Administrative Officer (principal executive officer) 
 
Date:         March 1, 2013        
 
By (Signature and Title)     /s/ Stephen D. Foy                              
                                                   Stephen D. Foy
                                                  Vice President and Controller (principal financial officer) 
 
Date:         March 1, 2013