The Taylor's checkerspot (Euphydryas editha taylori) was once found throughout grasslands in the Willamette Valley, Puget Sound, and south Vancouver Island. The historic range and abundance of the Taylor's checkerspot is not precisely known because exhaustive searches did not occur until recently. Northwest grasslands were formerly more common, larger, and interconnected - conditions that would have supported a greater distribution and abundance of Taylor's checkerspot. Before its dramatic decline, the Taylor's checkerspot was documented at more than seventy sites in British Columbia, Washington, and Oregon. The range of the Taylor's checkerspot has contracted severely. Currently, it is found at one location in British Columbia (rediscovered in 2005 after it was thought to be extirpated) and one locale in Oregon's Willamette Valley. Willamette Valley prairies support a wide range of interesting plants. Because plants are the core of the prairie, prairie preservation and management should start with a fundamental understanding of plants.