The IMBA was formed in 1988 by the Concerned Off Road Bicyclists Association, Bicycle Trails Council of the East Bay, Bicycle Trails Council of Marin, Sacramento Rough Riders and Responsible Organized Mountain Pedalers. Gibson Anderson of Sacramento was the IMBA's first elected executive director. In 1993, IMBA hired Tim Blumenthal, a former IMBA board member and cycling journalist, to serve as their second executive director. When Blumenthal began, the organization had roughly 1,200 individual members and about 60 affiliated clubs. The headquarters moved to
Boulder, Colorado, in 1994. In 1997, an international summit was held in Switzerland. It held educational outreach programs, such as the Trail Care Crews, which was sponsored by
Subaru Corporation. At the end of 1999, IMBA had more than 28,000 individual members, 14 staffers and a budget of $1.2 million. In 2006, IMBA's membership grew to 32,000 members, with a staff of 26 and more than 600 affiliated clubs. ==Affiliated organizations==