Sulphur Trails Smart Sizing Project

Mountain biking on easy trails Mountain biking on difficult trails with lots of rocks

*Photos courtesy of Singletrack Trails

(updated August 26, 2019)

Over the next 5-10 years, the Sulphur Ranger District will be implementing a trail system redesign project in the in the Winter Park and Fraser area to make the system more environmentally sustainable and socially compatible. The project aims to improve trail connectivity with existing trail networks in the Winter Park and Fraser areas by constructing new trails and rerouting existing trails creating a loop system with varying difficulty levels close to communities for mountain biking, hiking, and other trail users. Improving trail signage, maps, and trailheads are also part of the effort, providing better wayfinding to keep bikers on legitimate routes. The new sign system provides a difficulty rating for mountain bikers identical to what is found at ski areas.

The final decision, which was signed in Sept. 2017, includes new trail construction, trail reroutes, trail width reductions, trail-to-administrative road conversions, trail bridge construction, trailhead enhancement, and closing and decommissioning system and non-system (social or user created) trails. It also limits bicycle use to designated National Forest system trails and roads. Implementation is now in its third season.

Organizations such as Headwaters Trails Alliance, International Mountain Bike Alliance and Colorado Parks and Wildlife have been integral partners in the project, raising funds, providing input and managing implementation.

HTA has created a map that the Forest Service hopes will eventually become the official trail system map for the area.


Sulphur District Ranger Jon Morrissey released his final decision on August 29, 2017.

To date, nearly 6 miles of new bicycle trail has been constructed or reconstructed, while 1.6 miles of unneeded trail has been decommissioned.  In addition, 28 directional signs have been installed. An additional 1.5 miles of trail are planned for construction and reconstruction and additional 23 signs are planned for installation by the end of the 2019 operating season.

In August 2019, new regulations went into place that limit bicycles to designated roads and trails on the Arapaho National Forest in Grand County. The regulation applies to all types of bikes in summer and winter. In addition, two designated trails will be off limits to bikes in winter, including Tipperary Creek (N68) and Flume (N82).