Hoffmeister 1939 Microtus richardsonii July 29 Staywhile Sq. 5150ft, Columbia Co., Idaho. Caught a young male of this species in a trap that I had out the previous night and day. The trap was set in sparse, green grass near a log which had fallen across the small stream here. I had many other traps set in similar situations, but only caught this one Microtus.