Explanation of Names
The recently coined common name "Variable Checkerspot" was created to cover the lumping of E. anicia into E. chalcedona, which resulted in an indeed highly variable hodge-podge of different looking insects all bearing one species name.
The older common name, and more appropriate is the "Chalcedon Checkerspot".
The common name "Colon Checkerspot" was based on one of the subspecies of E. chalcedona, but that particular name was often widely used beyond the range of the particular subspecies.
Additional common names that are sometimes published are based on other of the regional subspecies names.
Identification
Similar to E. anicia, but generally larger, mostly found at lower elevation, and more black and white in appearance (with orange above reduced in comparison with that species). Where they occur together, this species tends to start flying earlier in the season. More orange populations occur in some of the higher mountains that look very like E. anicia, and are grouped under a separate heading.
Range
Primarily relatively near the Pacific Coast, west of desert areas, in areas of broken terrain, from northern British Columbia to northern Baja California Norte. Inland in mountains of eastern Oregon and Washington, across northern Idaho and just into extreme western Montana. Also inland in desert mountains across the Mojave and Sonoran Deserts of southern California and Nevada into southern Arizona and perhaps northwestern Sonora.