Many clubbers have done this one, close to DC, in the past. A good one for those tri-ing for their first century or metric:
"The 17th Annual Annapolis Bay Country Century offers a fully sagged tour of the Chesapeake Bay's western shore and is hosted by the Annapolis Bicycle Racing Team. There are rest-stops to enjoy the scenery and to refuel, clearly marked routes with easy to read cue sheets and bike mechanics to assist you. A portion of the proceeds benefit the Chesapeake Bay Foundation and the St. Leonard Fire Department.
Entry for all distances (100mile, 50mile, 60km and 25mile) is now closed but registration is available day of as well as tomorrow and Friday evening at ABRT's sponsor, Parvilla Cycle and Multisport.