New to this list: bicycletouringoncarfreepaths.org

This is a "work in progress", a new website still under development. From one of the authors,

"The website collects and shares information on how to do the great long-distance car-free bike paths in North America -- where the paths are, narratives on their settings in nature and history, information on lodging and camping, restaurants and food, ice cream and beer, bike shops and shuttle services -- basically, what the touring cyclist would want to know to plan a trip that could be across the state or across the continent."

Worth a visit if only to see their page on the C&O Towpath.

Rails to Trails Conservancy

Rails-to-Trails Conservancy is a 16-year-old nonprofit organization dedicated to enriching America's communities and countryside by creating a nationwide network of public trails from former rail lines and connecting corridors.

American Trails

An organization dedicated to promoting a national network of trails. This website contains much information on building and maintaining all kinds of trails.

Washington Area Bicyclists Association

The largest bicycle association and resource in the DC Metro area. Their website has much usefull information on bike routes throughout the area.

BikeWashington.org

Lists many rides and trails in the DC area, with good maps and ratings for terrain, traffic and scenery.

montgomerytrails.org

This Parks Division official website provides a description and map of all trails in the Montgomery County Parks.

Metropolitan Branch Trail Site

This proposed greenway would be a seven-mile linear park and trail running parallel to Metro's Red Line from Union Station to Silver Spring. It will connect directly to the CCT and to the National Mall to form a continuous 24 mile trail loop.

Friends of the W&OD

Information and a detailed map of the W&OD Trail in Northern Virginia.

Kathy Bilton's C&O Canal page

An amazing wealth of information on the canal and the towpath.

The C&O Canal Association

The site has info on C&O Canal history, current conditions and volunteer restoration activities, There is also info on joining the Association to help out.

The Washington Post Web site

Has links to numerous bicycle associations.