The National Forest System contains the largest network of trails in the world but lacks the resources and staff to keep up with growing recreation demands, according to the first government study on the topic in nearly 25 years. And two national public lands groups who requested the study—one of which is a trail riding group—say the results spell out the need for improved investments for the forest service trail system, including more reliable funding and a more systematic approach to organizing volunteers.

According to the study from the Government Accountability Office (GAO), a non-partisan government research wing, forest service trails are receiving more use than ever even as the maintenance and reconstruction backlog ballooned to $524 million in 2012. That figure has increased by more than half since 1989, the last time the GAO analyzed the national forest trail system.

While more people than ever are heading into national forests, only one quarter of all trails are maintained to standard. According to the report, this backlog prevents public access, poses dangers to public safety, and degrades clean water.

The Wilderness Society and Back Country Horsemen of America originally requested the study from several Congress members including Rep. Mark Simpson of Idaho, Rep. Cynthia Lummis of Wyoming, and Rep. Jim Moran of Virginia. The groups say the report’s findings present cause for concern but are not an insurmountable challenge.

According to The Wilderness Society, the most straight-forward solution is more reliable trail funding to better match