When the community gathers on Saturday, September 21, to celebrate the 10th anniversary of the expansion of the Peterson Ridge Trail System, they’ll be celebrating a grassroots effort that actually evolved over more than two decades.

As mountain-biking began to catch on in the early 1990s, an informal group of enthusiasts started building a place to ride at the south end of Sisters.

“Early ’90s, mountain-biking was booming and everyone was, like, ‘where do we ride?’” cyclist and bike-shop owner Brad Boyd said. “And even though we’re blessed with a lot of double-track — Forest Service roads to ride — people want to ride single-track.”

Work parties comprised mostly of riders laid out trail starting right on the southern edge of town. In those days, irrigation canals ran through the area, which required bridges.

“We got a bunch of people together and some high school kids and had some work parties with the Forest Service and built those bridges,” Boyd recalled.

The result was a trail configured like a “lollipop”: nine miles out-and-back with an approximately 3/4-mile loop at the top. It was a popular trail, but really only fully appreciated by mountain-bikers and some hikers. The City of Sisters nearly pushed it aside to make room for its sewer treatment facility. Boyd, who was serving on the city council at the time, advocated for retaining the trail.

Then, in the early 2000s, Sisters resident John Rahm turned a passion for mountain-biking loose on what would eventually become a major expansion of the trail.

“I just got really excited about mountain-biking,” Rahm said. “Once I got a really good bike, I was out there all the time. The trailhead is 300 yards from my house and I just noticed that there were some problems.”

Portions of the trail got very sandy and difficult to navigate, especially in the dry summer months. Rahm found a solution in bentonite clay, which firms the soil, and he and other cyclists added the clay to the trail.

Rahm and other riders saw greater potential in the trail.

“What we really need is a trail going out and a trail going back,” he thought. “I eventually put in a proposal to the Forest Service — really just kind of an informal thing.”

It took a few years to gain traction, but then-Sisters Ranger District Ranger Bill Anthony, himself an avid cyclist, got behind the project. The community raised the thousands of dollars required to do an environmental analysis, flagged the proposed route and organized to get the work on the ground done.

In a remarkable community effort, community members from across Central Oregon built and improved 20 miles of trail in 20 months, completing a major expansion in December 2009.

The trail is regarded as “fast and flowy,” and a fun ride for a wide range of cyclists. A beginner can have a good time and want to come back. An expert can have a good time and want to come back.

The accessibility of the trail from downtown Sisters and the views from the top add to the attraction.

“It’s a destination trail,” Rahm said. “People come here just for that. I think it’s the primary recreational amenity that the city has.”

Sisters Trails Alliance (STA), which coalesced in part around the creation of the trail, maintains the trail and has created maps for riding, hiking, and equestrian users.

STA has planned a series of hikes, rides and other activities to celebrate the trail on September 21. Registration is open until the activities are filled. For more information, visit http://www.sisterstrails.org.