[4] American naturalist and writer John Kirk Townsend collected the type specimen in 1835, which accounts for the second part of the name.

The upper surface is dark brown with many guard hairs with black tips and the underparts are paler.

Its range extends from Vancouver Island, British Columbia southwards through Washington state and Oregon to Humboldt Bay in California.

Nests may be built on the surface of the ground or on hummocks, and this allows the vole to live in seasonally-flooded areas where its burrows are sometimes underwater.

They also store the bulbous roots of American wild mint, consuming them during the winter even though plenty of succulent green food is available at that time.

Over the long term, the population seems to be steady and in some localities this vole is very plentiful, having been recorded at densities as high as eight hundred individuals per hectare.