_Specimens examined._--Total, 22: Prater Canyon, 7600 ft.,
76283-76287; Sect. 27, head of east fork of Navajo Canyon, 7900
ft., 69442; Far View Ruins, 7700 ft., 69443, 79223-79224; 2 mi. NNW
Rock Springs, 7900 ft., 69444-69446; Park Well, 7450 ft.,
69447-69453; rock ledge at head of Spruce Tree Canyon, unnumbered
specimen in Denver Museum; Headquarters, MV 7895/507, 7896/507.
The first specimen of the Mexican vole from Colorado was obtained on the
Mesa Verde and has been reported by Rodeck and Anderson (1956:436).
Specimens have now been taken at seven localities on the Mesa. Prater
Canyon is the only one of these localities at which any other species of
vole was taken. There _Microtus longicaudus_ and _Microtus montanus_
were also obtained. Judging from the vegetation at the above localities,
_M. mexicanus_ is to be expected in drier areas with less cover than _M.
montanus_ inhabits, and in areas having less cover than those inhabited
by _M. longicaudus_.