There are only 2 Pyrgus species known from Maryland, the Grizzled Skipper (P. centaureae) and the Common Checkered Skipper (P. communis). I believe the butterflies in my photographs represent the latter species. The photos above and on the left are of the same individual, while the one below, photographed about a week later at the same location (end of September-beginning of October of last year), is a different individual, because the fringes of its hind wings are more complete than those of the earlier individual. The location was a highly disturbed open field near a large creek and a busy road (East-West Highway) in Riverdale, Prince George's Co., Maryland.
The range of the Common Checkered Skipper covers most of the temperate North America extending south to the mountains of northern Mexico. Apparently, the species cannot survive very cold winters. A few days ago Firefly Forest Blog had pictures of a male Common Checkered Skipper from Arizona.
In contrast, the Grizzled Skipper is a more widely distributed Holarctic species, whose range extends not only to Alaska, Labrador and the arctic Quebec, but also across Asia to northern Europe.