The giant Palouse earthworm (Driloleirus americanus) is a rare and elusive species found only in the Palouse Prairie of the Pacific Northwest. Discovered in the early 20th century, this earthworm is known for its impressive size, with individuals reaching lengths of up to three feet.

The giant Palouse earthworm is a key component of the prairie ecosystem, contributing to soil health and nutrient cycling. Its rarity and elusive nature have made it a subject of interest for researchers studying soil ecology and conservation.

Conservation challenges for this species include habitat loss due to agricultural development and soil degradation. Protecting the giant Palouse earthworm involves efforts to preserve and restore its prairie habitat, as well as conducting further research to better understand its ecological role and needs.