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
DATED JANUARY 16, 1996
The sales charge in the secondary market will
reflect different rates depending upon the maturities of the
various underlying Securities as follows:
(as percent of bid (as percent of
Time to Maturity side evaluation) Offering Price
Less than 1 year 0% 0%
Over 1 year to 2 years 0.756% 0.75%
Over 2 years to 3 years 1.523% 1.50%
Over 3 years to 6 years 2.564% 2.50%
Over 6 years to 10 years 3.627% 3.50%
Over 10 years to 14 years 4.712% 4.50%
15 years and over 5.820% 5.50%
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.
