[2] Like its cousin, the giant Palouse earthworm (Driloleirus americanus) of Washington, this species can grow to lengths in excess of 3 feet (0.91 m) and up to an inch (2.5 cm) in width.

They tunnel deep into the soil and are known to dig permanent burrows fifteen feet below the surface.

However, during the wetter seasons, they are found closer to the soil surface feeding on the rich layers of accumulated organic material.

[3] Because this species is so elusive, being last sighted in 2008, it is very difficult to estimate populations or assess potential threats.

In the Willamette Valley, less than one percent of the original native grasslands remain, and conversion of land for agriculture, industry, and housing development has eliminated much of this species’ suitable habitat.