Smith's work was based on four specimens sent to him by R. It had been described as 'very common' in the Palouse region in the 1890s, according to an 1897 article in The American Naturalist by Frank Smith. The earthworm burrows deep during summer droughts and enters a state of aestivation. It is thought to sustain the earthworm during dry seasons. The fertile soil consists of deep loess hills enriched with volcanic ash and rich layers of organic matter. This species' native habitat consists of the bunch grass prairies of the Palouse region. Prior to its rediscovery in 2010, the worm was believed to give off a scent similar to that of the lily flower when handled and that it was able to spit in self-defense however, the specimens captured did not exhibit these capabilities. They are related to a species in Australia that is a true giant at 3.3 ft (1.0 m), the giant Gippsland earthworm. Typical adult specimens are about 8 in (20 cm) in length.

Little is known about the giant Palouse earthworm.

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