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Rule 497(d)
DEAN WITTER SELECT MUNICIPAL TRUST
INSURED CALIFORNIA SERIES 57
INSURED CALIFORNIA INTERMEDIATE TERM SERIES 4
INSURED INTERMEDIATE TERM SERIES 12
LONG TERM PORTFOLIO SERIES 120
SUPPLEMENT TO PROSPECTUS
SEPTEMBER 11, 1995
Effective September 1, 1995, The Trustee is The Chase
Manhattan Bank (National Association), a national banking
association with its principal executive office located at 1
Chase Manhattan Plaza, New York, New York 10081 and its unit
investment trust office at 770 Broadway, New York, New York
10003. The Trustee is subject to supervision by the Comptroller
of the Currency, the Federal Deposit Insurance Corporation and
the Board of Governors of the Federal Reserve System.
The prospectus included in the Registration Statement for
Dean Witter Select Municipal Trust, Insured California Series 57,
Insured California Intermediate Term Series 4, Insured
Intermediate Term Series 12 and Long Term Portfolio Series 120 is
hereby incorporated by reference.