» AC100 RaceBook
   The official record and program of the Angeles Crest 100 Mile Endurance Run. Includes course and driving maps for runner and crew. 1986-2001 information.
   http://www.geocities.com/ac100racebook/index.html

» American Ultrarunning Association
   Membership details, race listing, USA National Ultra Team, description of the organization and related links.
   http://www.americanultra.org/

» Australian Ultra Runners' Association
   Seeks to promote ultramarathon running in Australia. Provides a race calendar, results, news, and links.
   http://www.coolrunning.com.au/ultra/

» Cascade Running Club
   Hosts 100 mile, 50 Mile and 50K minimalist runs in Washington. Includes club information and race details.
   http://www.cascaderunningclub.com/

» Endurance Sport Club
   International organization, based in Canada, that sponsors a number of fat-ass style ultra-races. Includes membership information and race calendar.
   http://www.clubfatass.com/

» Extreme Ultrarunning
   Resources, links, and general information. Includes runners' profiles, calendar, photographs and race reports.
   http://www.extremeultrarunning.com/

» Hal Higdon: On The Run - Ultramarathon Training
   While focusing on the Comrades Marathon, author Higdon provides a training plan useful for a wide range of ultras.
   http://www.halhigdon.com/ultramarathon/ultramarathon2000.htm

» International Association of Ultra Runners
   Provides organizational information, newsletters, race listing and coming events, training tips, and links. English and Chinese versions.
   http://www.iau.org.tw/

» Kansas Ultrarunners' Society
   Includes event descriptions, member biographies, pictures, newsletters and membership information.
   http://www.ultrarunners.info/

» Kevin Sayers UltRunR Site
   Resources and opinions on topics ranging from training and racing tips to equipment recommendations.
   http://www.ultrunr.com/

» Marathon and Beyond
   Published six times a year - website contains tables of content, sneak previews and ordering information.
   http://www.marathonandbeyond.com/

» Marathon of Britain
   News, the team, photographs, faq's, and community.
   http://www.ambitionevents.com/mob/

» Multidays.com
   Resource for multi-day events with calendars, news, results, and training information.
   http://www.multidays.com

» New York Ultra Running
   Contains details about races in the area, highlights, pictures, directions, and membership details.
   http://www.newyorkultrarunning.org/

» North Texas Trail Runners
   Information on trail running and ultra running in North Texas. Features calendar listings and a news/opinion section.
   http://www.nttr.org/

» Sri Chinmoy Marathon Team International
   Sponsor of multi-day races, including the world's longest certified race of 3,100 miles, triathlons, and many ultra events in more than 30 nations. Includes news, photos, race information, library and links.
   http://www.srichinmoyraces.org

» Sri Chinmoy Marathon Team New York
   Multi-day events, including an annual 3,100-mile race. Information on upcoming races and events, articles, and contact information.
   http://www.srichinmoyraces.org/us/

» St. Louis Ultrarunners Group
   Provides club news and events, including registration materials.
   http://www.stlouisultrarunnersgroup.net/

» Stan Jensen's Ultramarathon Guide
   Provides general information on the sport, especially focusing on northern California. Includes information and statistics for the top races in the USA, as well as personal achievements, and goals.
   http://www.run100s.com

» Team CRUD (Coloradans Running Ultra Distances)
   Ultra trail running information, photographs, news, and links.
   http://www.teamcrud.com/

» The 100km Association
   Club serving Britain. Includes news and events, club information, message board, and race results and reports.
   http://www.carey.abelgratis.co.uk/100km/index1.htm

» Ultra Adventures
   Comprehensive regional ultrarunning resource focusing on North Carolina and the Mid-Atlantic region.
   http://www.ncultra.org

» UltraOz
   Includes news, links, and race descriptions.
   http://www.ultraoz.50megs.com/

» UltraRunner.net
   Resource for clubs and races in North America with upcoming events, pictures, related links, mailing list and course descriptions.
   http://www.ultrarunner.net/

» Ultrafit Endurance Sports
   Company that specializes in products designed for the endurance athlete.
   http://www.ultrafit-endurance.com/

» Will Brown's Umstead 100 Report - 2001
   Will Brown conquers the 100 mile distance at the 2001 Umstead 100 Mile Run in Umstead State Park, Raleigh, North Carolina, April 7-8, 2001.
   http://www.geocities.com/madeads/will01-100.html