NA (Canada to Mexico)
(2):
M. bicolor in so. Canada and n. US coast to coast (south to CA and in the mountains west of the Rockies and in the Great Basin Desert),
M. wickhami in sw. Canada and w. US east to ND-IL-TX; the remaining 2 spp., locally in sw. US (
C.W. O'Brien's comment and
(1))