Front:
ARIZONA SPILLWAYS
AND LAKE,
BOULDER
DAM
Back:
29067N
The foundation and abutments of Boulder
Dam are rock of volcanic origin, geologically
termed "andesite breccia,” hard and very dur-
able. The canyon width at low water level is
about 300 feet, and at the crest of the dam,
1,282.
T.
CO
WATTERS WHOLESALE CO., LAS VEGAS, NEV. CIY
