_Specimens examined._--Total, 16: Upper Well, 7575 ft.,
69454-69465; 1/4 mi. N Middle Well, 7500 ft., 69466-69469.
The voles were trapped in the dry but dense meadow of grass and sedge
covering the floor of the canyon (see Plate 1). _Sorex vagrans_ was
trapped in the same places. Four of the females of _M. montanus_ trapped
on September 3, 1956, were pregnant.