| Albany Running Exchange: Trail running club based in Albany, New York. Includes summer trail run series, results, calendar, photos, and member news. |
| All American Trail Running Association (AATRA): Membership application and extensive collection of links and information on events, trails, equipment, and race results. |
| American Discovery Trail: Learn about the first running trail that crosses the entire nation. |
| BC Trail Running: Offers information on trail running in British Columbia, Canada. Includes articles, photos, and links to several trail series. |
| eHow to Choose Trails for Trail Running: Tips and information about trail running. Requires free membership. |
| Gil's Athletic Club: Trail running club based in Topsfield, Massachusetts, sponsoring several trail races (primarily ultras). In addition to race information, includes weekly runs, guide to area trails, and photos. |
| Irish Mountain Running Association: Irish mountain running. Trails, races and links on the Island. |
| Mountainrunning.com: Rocky Mountain trail guides with maps and descriptions. World mountain running trophy information on venues, maps, results. Guide to trail accommodations available. |
| New England Trail Runner: Extensive listing of New England area trail racing and running information on the web. Includes race results posting and trail running club information. |
| Northern Arizona Trail Runner's Association: Promotes trail running in Northern Arizona, in the United States. Contains a listing of upcoming races, related links, history of the organization, pictures, membership details, race summaries, and message board. |
| Peak Trail Runner: A guide to trail running in the UK Peak District national park. |
| Perry Scanlon's Home Page: Contains photos and links to trail and workout information near Palm Springs, California, as well as specific information for the Skyline Trail. |
| Redwood Trails: Information on a series of trail runs in the Bay Area of California. Race distances range from 5k to the marathon. |
| Run Hayward Hills Trails: Trails of Hayward, California. Great for running and riding ATB. |
| Shenipsit Striders: Trail running club in Somers, Connecticut, sponsoring the Soapstone Mountain races as well as weekly training runs. Includes race information and results, photos, and links. |
| Team Gloucester: Trail running club in Gloucester, Massachusetts. Cape Ann trail information and maps as well as an extensive trail race calendar for New York and New England. |
| Trail Runner Magazine Online: Running, health, travel, and training, race results and race event calendars. |
| USTrailrunner: Includes gear reviews, race calendar, online store, and discussion board. |
| Western Mass Athletic Club: Trail running club in western Massachusetts. In addition to club news, includes information for several trail and snowshoe races as well as the Grand Tree Trail Race Series. |
Classical
