Washington DC is such a great area to immerse yourself in outdoor hobbies. Drive an hour (more or less) to the west, and you've got mountains, drive an hour (more or less) to the east, and you've got the coast. My membership in the AMC (Appalachian Mountain Club) is some of the most satisfying money I spend each year.
A few years ago, I took a job for the summer in the Arkansas Ozarks. The job turned out to be more of a nightmare than the five-week idyllic working vacation I had in mind when I took the job. After about a week of some serious liver-pickling drinking (easy to do in party-town Eureka Springs), I was sitting out by Beaver Lake, and I saw a guy paddling around in a kayak. He told me where there was a nearby outfitter, so completely on impulse, to keep my mind off drinking, I bought a 10' kayak and haven't looked back. I bought it as an alternative to booze, and it has remained so several years and many paddle trips later.