497 1 d621491d497.htm BLACKROCK CALIFORNIA MUNICIPAL OPPORTUNITIES FUND BlackRock California Municipal Opportunities Fund
LOGO    787 Seventh Avenue
   New York, NY 10019-6099
   Tel: 212 728 8000
   Fax: 212 728 8111

October 24, 2018

VIA EDGAR

Securities and Exchange Commission

100 F Street, NE

Washington, DC 20549

 

Re:

BlackRock California Municipal Opportunities Fund, a series of BlackRock California Municipal Series Trust

    

(File No. 002-96581 and File No. 811-04264)

Ladies and Gentlemen:

On behalf of BlackRock California Municipal Series Trust and pursuant to Rule 497(c) under the Securities Act of 1933, as amended, attached for filing are exhibits containing interactive data format risk/return summary information that mirrors the risk/return summary information in the Prospectus dated September 28, 2018, for BlackRock California Municipal Opportunities Fund (the “Fund”) filed under Rule 497(c) with the Securities and Exchange Commission on October 3, 2018 (the “497 Filing”). The purpose of this filing is to submit the 497 Filing in XBRL for the Fund.

Any questions or comments on this filing should be directed to the undersigned at (212) 728-8629.

 

Very truly yours,
/s/ Mia G. Pillinger
Mia G. Pillinger

Enclosures

 

cc:

Benjamin Archibald, Esq., BlackRock Advisors, LLC

    

Elliot J. Gluck, Esq., Willkie Farr & Gallagher LLP