HESSTON -- The new Allegrippis Trails bordering Raystown Lake in Huntingdon County were weather-tested before they officially opened May 9.

It had rained off and on for the previous eight days and out-of-state mountain bikers were calling to see if the dedication ceremony would be held as scheduled.

It did, thanks to the quality of the design and construction of 32 miles of single-track, multi-use trails expected to attract an additional 9,800 visitors a year to the 1.5 million visitors who visit the lake annually. There were some soft and muddy spots on the trails that sunny and breezy day, but the overall conditions were surprisingly good.

"These trails are built world class," said Mike Van Abel, executive director of the International Mountain Bicycling Association in Boulder, Colo. "We build them to fit into the environment and this is an awesome landscape."

The association's Trail Solutions, working in partnership with the Army Corps of Engineers (which owns the land), the Friends of Raystown Lake and other trail-contracting firms, built a loop trail system that also can be enjoyed by hikers, runners, birders, cross-country skiers and snowshoers. They are well worth the 130-mile drive from Pittsburgh.

The multiple-routes trails are in the Seven Points area of Raystown Lake, the largest inland lake in Pennsylvania. Some overlook the 8,300-acre lake. There is no fee to access the trails or the Seven Points area. The trails are expected to help the lake become a year-round destination by extending its recreational season deeper into the fall, winter and spring.

The 23 color-coded trails range in difficulty from green (easiest, family-friendly and closest to the parking lots), to blue (moderate ) and black (most difficult). Four are rated easiest, 15 are moderate and four are difficult.

Riders on blue trails can expect the usual obstacles: roots and rocks. Those on black trails will encounter more of the same plus significant leg-and-lung elevation changes and longer distances.

"This is going to be one of the premier mountain bike trail systems in the state," said Ed Dobo, 46, of Clearfield County, who was riding with his sons, Ed II, 22, and Bill, 20. "There's camping here in the park and overnight accommodations nearby so you can make a weekend of it."

"These trails are great," said Joe Daversa, 60, of Harrisburg, as he took a break in the parking lot of the Raystown Lake Visitors Center. "They're wider than what I'm used to and they need to be worn in, but they are awesome."

Evan Gross, president of the Raystown Mountain Biking Association, agreed.

""I've never ridden on trails like these," he said, as he prepared to saddle up for another ride. "They are so well done. Riders of all abilities will find as much challenge as they want."

Mr. Van Abel said Allegrippis represents one of IMBA's single biggest trail systems in terms of trail mileage, quality and number of trails. The association has members in all 50 states and 40 foreign countries who annually contribute more than 1 million hours to trail work projects on public land.

Ron Rabena, president of the Friends of Raystown Lake, said more than 100 volunteers donated more than 2,300 hours toward the construction and maintenance of the Allegrippis Trail system. Allegrippis, believed to be a Native American word, is the name of a nearby ridge.

"When the project started, it was a 'build it and they will come' proposition," said Frank Maguire of State College, director of IMBA's Mid-Atlantic Region.

Now there is a bike shop in town, Rothrock Outfitters, and the Raystown Mountain Biking Association, which didn't exist 18 months ago, has more than 30 active members, he said.

"The end result is a unique trail system that will benefit the region and community for years to come, including an additional estimated $1.2 million in annual revenue into Huntingdon County."

The Deer Loop's Buck, Fawn and Doe entry-level green trails offer a 3-mile ride that features easy descents, easy climbs, a few roots and rocks, a wooden bridge and extended curves through wooded terrain. All in all, it involves about 200 feet of climbing.

"It's a roller coaster on two wheels," Mr. Rabena said, referring to the entire trail system that was carefully carved through stands of Appalachian hardwood trees, young evergreens and a few meadows.

The down-up-down-up design, which includes some level stretches, helps bikers to control their speed. It also helps control erosion.

The design also enables riders to connect to other trails. The Deer Loop, for example, links to Osprey, a moderate trail that, in turn, connects to Hydro, which is rated difficult.

Mr. Maguire said the Hydro loop "delivers the full Monty," with a 3- mile descent to the shore of Raystown Lake "and a nice undulating climb back to the Deer Loop.

"First-time visitors need to be careful [because] ... you never settle into the climb. You pedal as if the next roller is the last one and often find yourself spent before you're halfway done. The total elevation change for this ride is 1,500 feet," he said.

Translation: pace yourself.

For a real workout, Mr. Maguire recommends Ray's Revenge, a 4.5-mile stand-alone trail "that deserves its expert rating. The preferred direction is to ride it south to north so you end up at the vista [of the lake] for a reward."

Park ranger Allen Gwinn said the Corps of Engineers and IMBA teamed up in 2002 to develop mountain-biking opportunities on Corps property. In 2003, Raystown Lake was selected as one of 12 national demonstration sites and a half-mile demonstration trail was built. A second demonstration trail was built in 2006.

The major funding was provided by the state Department of Conservation and Natural Resources ($150,000) and the Appalachian Regional Commission ($170,000). Friends of Raystown Lake contributed $35,000 in in-kind services and REI contributed $5,000 for volunteer backpacks, first-aid kits, supplies and money to buy benches for the trail. Its employees also donated many hours of time.

"More than 400,000 visitors stay in our campground every year," Mr. Gwinn said. "Many bring their bikes and ask where they could ride them. The park roads used to be their only choice. Now they've got a lot of choices and we're looking forward to telling them all about them."

For more information, go to http://raystown.org/outdoor-fun/allegrippis-trails.html, www.TheAlleghenies.com or call toll-free 1-800-458-3433.