Biking long has had a romantic appeal--it was one of the few shared pursuits of Hemingway and Henry James--but for years I'd let it fall out of my life. The images of hurtling along dirt paths had faded into memory's closet amid Little League runner-up trophies and prized Kiss 45s.

The years hum past, but a secret itinerary of visited trails remains. The gut sensation of slope-side gravel giving way does not change no matter what path or bike you ride, but it took just a few moments into a recent trip at Louise F. Cosca Regional Park in Clinton to realize most everything else had.

What I last searched for a decade ago--fast descents and snaky trails--at first seemed forbidding. The rear brakes of my rented mountain bike closed in a downhill friction-clamp until the path flattened into a straightaway lined by ferns. As I gained control of my speed, the sounds of my gear shifts and tires bouncing on roots and sticks flushed a black bird from its low cover.

Somewhere along the way I'd missed the path to Cosca Lake and less difficult terrain. Instead I paralleled a streambed and experimented with the 21 gears. By the time I splashed across a shallow cut farther into the 500-acre park, the excitement of riding had returned. My rented Trek with its complex derailleur was a '90s update on my long-since sold Univega and the high school 10-speed and the one-speed with banana seat and chopper handlebars, but the thrill was familiar.

"It's the same," said Forestville's Tracy Gary, 32, who had completed a 15-mile trip through the park. "But you are getting a little older. . . . You have to work on your wind. As a kid you were just riding and playing."

Mountain biking is a relatively new arrival at the park, which in its 32 years has provided multiple outdoor offerings: tennis, baseball, picnicking, camping, hiking and horse riding. Knobby tire tracks, however, are spreading.

Over the past two or three years, mountain bikers of varying dedication have passed horseback riders as the most frequent users of the trails. The Maryland-National Capital Park and Planning Commission, which maintains the park, has adapted to changing demand and allows two-wheelers free rein.

"It's just inside the playground area," Park Police officer Jeff Claggett said. "That's the only area that we don't allow bikes."

Gary and Nathaniel Cary spent over three hours traversing Cosca on Sunday. It is a place they know well. During the past five years, Nathaniel Cary said, he'd bicycled in the park more than 100 times. He pedals with an intensity that matches the terrain I'd seen.

"You stay in low gears [at Cosca]. . . . Cycling for me is endurance," said Cary, 34, who often rides in a group that includes his brother, Alfi, and Gary. "I've never broken anything [but] it breaks your spirit when you take a good fall."

Cary, who lives in Fort Washington, is quick to set the pace. "He'll pressure me a little bit," Gary said. "I try to keep up."

Although there are several good off-road places to bike in the county, including Cedarville State Forest in Brandywine and Jug Bay Natural Area hiking and equestrian trails in Upper Marlboro, word has spread about Cosca. Claggett said he can pick out the regulars.

The trails are not considered overly technical, especially the perimeter road, but its combination of ascents and dips and hairpin turns keeps riders on alert.

"We're seeing more bikers using" the park, said Sandy Lyon, the nature program and facility manager at Clearwater Nature Center, which is located on the grounds. "There aren't many areas . . . where you can have the hilliness and challenge. Most of the area is pretty flat in southern Maryland."

It did not take me long to realize the park presented a tough landscape after years away from the sport. But pedaling straight ahead seemed the only acceptable response and I eventually found my way back. Steep acceleration provides little time for idle recollection. It felt good to be on the move.

Questions? Comments? Do you know of a special place in the outdoors? We'd like to hear about it. Get in touch with John Mullen by writing him at: The Outsider c/o The Washington Post, 1150 15th St. NW, Washington D.C., 20071. Or e-mail him at mullenj@washpost.com

BIKING AT COSCA PARK

HOW TO GET THERE: Beltway to the Branch Avenue South exit, then right onto Old Branch Avenue. After veering left, Old Branch Avenue eventually turns into Brandywine. Continue until Thrift Road, then take a right. The park is located at 11000 Thrift Road.

* There are several on- and off-road biking clubs in the area, including Chesapeake Mountain Bike Club (Post Office Box 3932, Crofton, Md. 21114, or on the Web at www.annapolis.net/cmbc). The International Mountain Biking Association's Web site is www.imba.com.

* For mountain bike rentals: Mike's Bikes in Waldorf ($12.50 for half day, $25 for 24 hours) and College Park Bicycles ($30 per day, no half-day rentals).