Mountain bikers have gained a small foothold in the previously off-limits territory of America’s national parks.

The National Park Service recently signed a five-year agreement with the International Mountain Biking Association that could open to mountain biking hundreds of dirt roads in national parks across the country.

“This agreement represents a true breakthrough for mountain biking,” said IMBA Executive Director Mike Van Abel. “It opens the door for individual park units to partner with mountain bikers and investigate new riding opportunities on a case-by-case basis.”

IMBA has 32,000 members and 450 affiliated local clubs.

Two parks will be selected for pilot projects later this year. Mountain bikers and park officials will work together to identify what areas within the park are suitable for mountain biking. IMBA is soliciting suggestions of which parks should be used for the pilot study from mountain bikers across the country.

IMBA has cautioned mountain bikers not to get too excited about a wholesale shift in mountain bike restrictions in parks.

“Certain trails in units of the National Park System are administered and managed either exclusively or primarily as hiking and backpacking trails and will continue to be administered and managed as such,” the National Park Service maintains in the agreement.

While National Park Service rules require a lengthy process to open single-track to bicycle use, some dirt roads could be opened with a more straightforward administrative process based on language in the new agreement.

“While mountain bikers shouldn’t expect a revolution of new single-track in National Parks, the partnership signals an encouraging direction for the future,” said Pete Webber, IMBA communications director.

The National Park Service previously held that mountain biking was not compatible with the park service’s mission.

In the Great Smoky Mountains National Park, 80 percent of the trails and dirt roads on the North Carolina side of the park are open to horses. None are open to mountain bikes. However, it has become widely accepted in the trail community that mountain bikes have significantly less impact on trails than horses. A mountain bike’s weight is more evenly distributed and the wheels compact the trail bed, unlike the rotating action of horses’ hooves bearing large loads on small points.

But the level of impact to trails is not the reason behind mountain bike bans in national parks. While human powered, mountain bikes are still a form of mechanized recreation and not what the majority of Americans expect to see or encounter when visiting their national parks, the park service reasoned.

But the new agreement states mountain biking “is an appropriate recreational activity in some units of the National Park System,” representing a philosophical breakthrough to some extent.

“Mountain bicycling in authorized areas can be an excellent way to enjoy America’s outdoor heritage in a manner that is compatible with resource protection,” said Karen Taylor-Goodrich, the associate director for visitor and resource protection

“With enhanced communication and cooperation between IMBA and the National Park Service, mountain bikers can anticipate that cycling opportunities in national park units will continue to improve,” Weber said.