Hold on to Your Handlebars - A carefully executed partnership results in a sustainable mountain biking trail in Minneapolis.

By Margie Walz
September, 2007
Parks & Recreation Magazine

Minneapolis-St. Paul, Minn., may not be the first place that comes to mind when mountain bikers think of challenging trails and exciting terrain. But a new trail in the Twin Cities area is proof that park systems can create facilities that satisfy mountain bicyclists' desires while preserving a park's natural resources.

Of all the facilities operated by Three Rivers Park District in the suburban Twin Cities area, Murphy-Hanrehan Park Reserve is one of the least developed. The nearly 2,800-acre park reserve includes 1,200 acres of oak forest as well as a 200-acre protected natural resource sanctuary. But the recreation opportunities are in high demand because the reserve is located in Scott County, one of the fastest growing areas in the metropolitan area.

But there's plenty of park to go around. Murphy-Hanrehan is full of recreation potential - facilities include a boat launch, fishing pier and multi-use trails. Although Murphy-Hanrehan has no mountains, the park's topography is well-suited for mountain biking. The park reserve is located on a steep moraine of steep, tree-covered hills that dot the park landscape. For many years, mountain biking was permitted on a trail developed for cross-country skiing.

But the situation with the trail was far from ideal. Because it was located near a bird sanctuary, it could only be used for mountain biking between Aug. 1 and Oct. 31 each year. Additionally, erosion was a significant problem on the trail. Park District Landscape Architect Kelly Grissman explains that the trail was built on the fall line, characterized by nearly vertical up-and-down hills. Maintenance staff would repeatedly fill in the soil that had eroded, only to have it wash away again. Murphy-Hanrehan had available land and a trail that wasn't sustainable, something that members of the Minnesota Off-Road Cyclists (MORC) recognized. The grassroots organization dedicated to responsible, sustainable mountain biking approached park district staff about partnering on a trail project.

The partnership was launched in 2004, when MORC and the International Mountain Bicycling Association (IMBA) conducted a sustainable trail-building school at the park. During the school, representatives from MORC and IMBA worked with park staff to create a demonstration sustainable trail section. Another trail school was held in 2005, which included participants flagging the rough outline of beginner and intermediate-level trail features. This got the ball rolling for the sustainable trail design.

In addition to collaborating on the planning and construction of the trail, the park district and MORC also partnered on financing it. MORC pledged $30,000 to the project, and the park district budgeted $47,000, funding half the project; a matching grant from the Minnesota Department of Natural Resources (MnDNR) through Minnesota's State Comprehensive Outdoor Recreation Plan (SCORP) took care of the rest.

The trail project fit the priorities established in SCORP, which encourages park systems to strive toward facilities that balance recreation opportunities with protection of natural and cultural resources. SCORP calls on communities to improve situations where recreation is harming the natural environment. The new trail fit with this goal, since it replaced the previous erosion-prone trail with one that is sustainable.

Construction began in the fall of 2006 when the park district hired a crew from the youth organization Tree Trust to help with trail construction. Tree Trust was founded with the dual mission of helping to reforest the Minneapolis-St. Paul area in the wake of Dutch elm disease, as well as providing job opportunities for youth and young adults. The organization has grown to provide much more than reforestation. After park maintenance staff designed the structures, cut the lumber and completed some pre-construction work, Tree Trust took over. Their three-person crew installed six bridges and three boardwalks in 11 days. The bridges span small gullies and ditches on the trail, while the boardwalks allow the riders to traverse sensitive wetland areas without causing damage.

The Park District also utilized the help of a Sentencing to Serve (STS) crew for the trail construction. The team, administered through the Hennepin County Department of Community Corrections, removed debris and hauled the lumber to areas of the trail where bridges and boardwalks were to be located. It was necessary for the crew to hand-carry the lumber because the mountain bike trail is only two feet wide. But Brad Chock, a park staff member, says that the narrow trail, among other features, provides the kind of challenge mountain bikers love.

Approximately 6.9 miles of the 10-mile trail is designed for advanced riders. Specifically, the trail's advanced loop is more challenging than the other loops according to MORC Trail Steward Peter Crabtree. "It's a combination of factors: the higher and narrower bridges, a narrower tread (often cutting across very steep side-slopes); steeper, more difficult climbs and descent; and more technical features like rock gardens, large rocks to ride over and optional features like a log ride," he says.

The log ride has become a signature characteristic of the Murphy-Hanrehan trail. This idea was conceived as MORC representatives and park district staff were walking the proposed trail route during the planning process and discovered a downed tree that looked like it could work well as a trail feature. A flat surface was cut down the length of the log, creating a structure that bicyclists can ride on to test their skills. Before MORC members build additional technical features like the log ride, they discuss their ideas with Chock, who determines the park district's goals for the trail. Chock explained that he evaluates proposed technical features based on what will keep the trail safe, yet present a challenge for riders who want to try the optional features. The addition of even more technical features will be a gradual process during the next few years to help keep the trail experience interesting for repeat riders.

One advantage of collaborating with a grassroots organization like MORC is that the group's members volunteer to assist with maintaining and improving the trail. But Crabtree hopes that the trail's design will keep maintenance work to a minimum because of its sustainable design. Rather than being routed straight up and down hills, the trail was built on side slopes to shed water and prevent erosion.

"One of the biggest jobs MORC has is what we call deberming," Crabtree says. He explains that as bicycles travel

over an off-road trail, their tires push soil into a berm on the outside of turns. To prevent a rut from wearing into the trail path, MORC volunteers must travel the length of the trail, smoothing out the berms that have formed. "That's a pretty big job, especially with 10 miles of trail," Crabtree explains. "That's something we'll be constantly doing."

In order to assist with the maintenance of the narrow trail, the park has a two-wheeled helper - an off-road motorcycle called a Rokon. "We have all kinds of tools strapped to it," Chock said. "It's very handy."

Most park staff agree that it's a joy to maintain a new sustainable trail that provides mountain biking, hiking and snowshoeing opportunities. In addition, they say they learned so much about sustainable trail design through the partnership with MORC that they would welcome the chance to collaborate on future trails. MORC representatives have returned the sentiment, expressing appreciation for what they learned about working with a public agency through the partnership.

Chock says, "The park district has taken a tremendous leap in terms of what they're allowing riders to traverse." And his priorities have changed, especially when it comes to presenting trail users with challenges, he explains. "It used to be we were throwing rocks

What Is a Stacked-Loop Singletrack Trail?

The term "stacked-loop" refers to a trail's configuration and it includes some important features that help trail users determine the level of difficulty they wish to encounter. To use the trail at Murphy-Hanrehan, all users start out on the one-mile beginner loop. This part of the trail winds its way through open, rolling prairie. About two-thirds of the way through the beginner loop, trail riders come to an intersection with the intermediate loop.

If riders choose the intermediate loop, they quickly encounter rocks placed along either side of the trail and a log across it. These obstacles are designed to show riders that they're entering a more difficult part of the trail.

Along the intermediate trail, riders find the intersection with the advanced loop. There is also a set of obstacles at the beginning of the advanced trail: two sets of boardwalk steps with a narrow section in between for bikers to ride over.

According to the International Mountain Bicycling Association (IMBA), a singletrack trail is narrow enough so that riders must travel in a single-file line. The tread of a singletrack trail is usually two feet wide or less and a singletrack trail is nearly always natural surface (not gravel).

For park systems that are considering building their first sustainable mountain bike trail, IMBA has published books that are valuable resources. Two that Three Rivers Park District staff relied on are Trail Solutions: IMBA's Guide to Building Sweet Singletrack and Managing Mountain Biking: IMBA's Guide to Providing Great Riding. These books offer expertise on every trail topic imaginable - from a step-by-step guide to building a trail switchback to the key elements of a memorandum of understanding (MOU).