Where are you located? In PA I would hook up with Freeze Thaw guys (Justin) in State College to discuss their gravel endeavors around town. With Rothrock State Forest and events like the Transylvania Epic and Wilderness 101 0plenty of options.
If you're in the northeast I would look into the gravel available in the Adirondacks, VT has a trail from Massachusetts to Canada that's pretty well set, and places like Western Mass, NH, and Maine have many options for those who like to plan.
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!