The Mardon skipper is a rare northwestern butterfly with a remarkably patchy distribution. This tawny-orange butterfly has a stout, hairy body, and is less than 1 inch across. The upper surfaces of the wings are orange with broad dark borders. The lower surfaces are light tan orange, with a distinctive pattern of light yellow to white rectangular spots. Currently, the Mardon skipper is known from four widely separated regions: the South Puget Sound lowlands of Washington; the southern Washington Cascades; the Siskiyou Mountains of southern Oregon; and coastal hills of northwest California. In California, 2 isolated populations are known, located about 10 miles apart in serpentine-soil grasslands in Del Norte County.

Mardon skippers typically occur in small grasslands and meadows, where the caterpillars feed primarily on fescue grasses. Most known sites are in small openings within forests or woodlands. The Mardon skipper likely spends its entire life cycle in one location, and it does not appear to be a strong flier, so its ability to colonize new areas is probably limited.

Most known mardon skipper populations are small, less than 50 individuals. However, the number of documented locations for the species has increased from less than 10 in 1998 to as many as 65 range-wide in 2005, reducing the chance that local changes or events could decimate the species.

The species faces several threats, but the loss and degradation of habitat, as well as random, natural events, appear to be the greatest threats. A main problem for habitat is vegetation changes, caused by overgrazing, encroachment of nonnative and native vegetation into meadows and grasslands, and the succession from grassland to forest, in part due to the suppression of fires.

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