This was found along a remote trail that leads to the Patuxent River from Ferry's Landing Rd. While it is a public trail, its not advertised as such and seems to only be used by hunters or people fishing. It looks most like a Nomada sp. in one of my guide books but not quite the same. As I recall, it preferred sunshine, was always close to the ground, and was not bothered by my daughter's or my presence. It was on the forested part of the trail closer to the trail head, pretty far from the Patuxent River.