In south Puget Sound grasslands, mardon skippers use open, grass dominated habitat with abundant Roemer’s Fescue interspersed with early blue violet and select early blue violet and common vetch as nectar sources. Adult mardon skippers select for short, open-structured, native fescue grasslands, which provide access to nectar and oviposition plants and a requisite thermal environment. Mardon skippers on two south Sound prairies oviposited (laid eggs) on Roemer’s fescue, and females selected for small, mostly green fescue plants, in sparse, short-statured, and open-structured vegetation.