Craig Gangloff is making his way around Montgomery County's first Frisbee golf course when he is asked to demonstrate how to play an especially tricky "hole," a 195-footer that doglegs left.

He takes a quick, short step and lets his Frisbee-like disk fly. It rises swiftly as it whizzes along a tree-lined alley, reaching its peak at the break in the fairway. Gracefully, it begins to fall off to the left, narrowly missing an outstretched branch and spinning downward until it bangs off the metal basket-on-a-pole that serves as the Frisbee version of a hole and pin.

"Oooohhhhhh! Did you see that?" Gangloff yells, pumping his fist like a quarterback who has just completed a long bomb.

Gangloff's bending shot is no accident. He nearly duplicates the feat at another hole when his disk glances off the top of a pin standing more than 250 feet away.

The 26-year-old Colesville resident, who helped build the new course at Seneca Creek State Park near Gaithersburg, is part of a Frisbee movement that is changing the tie-dyed, laid-back image of the back-yard game. Fiercely contested Frisbee sports, or, more accurately, disk games, are becoming increasingly popular.

There are nine public disk golf courses in the Baltimore-Washington region and about 500 nationwide, Gangloff said.

The numbers might increase faster if more recreation officials were convinced that there is enough interest in disk golf to justify setting aside the land and paying for course maintenance, Gangloff said.

Gangloff, who works as a project manager for a small Bethesda construction company, got around those reservations by pledging to use volunteers to build the Seneca Creek course. He also contributed nearly two-thirds of the $7,500 cost of equipment. The rest he raised through donations.

"As soon as you say 'donate,' people get awfully receptive," Gangloff said.

The 18-hole course is set up on 25 acres of hilly land next to the Great Seneca Parkway and takes about an hour to play. Trees and shrubs dot the course, serving as obstacles.

Disk golfers must make their first throw from a concrete pad that acts as a tee. The next throw is made from wherever the disk lands.

The golfers continue along until the disk is flung into a metal basket suspended on a pole. Several chains hanging above the basket help deflect the disk into the "hole."

Work on the Seneca Creek course is expected to be completed later this month, but the pins are in place for play now. The park was host to its first professional tournament, the Maryland State Championship, last month.

Gangloff finished second in that tournament, but he said he was more thrilled by watching 93 competitors from 12 states and the District try his course.

"I got all my money back just watching their excitement," he said.

Even at a gathering billed as the largest noncompetitive Frisbee event in the nation, competition is making gains. Saturday's 14th National Frisbee Festival on the Mall in Washington featured demonstrations of several competitive disk sports. The most popular is arguably a football-like game called Ultimate, in which two teams of seven toss a disk up and down a field and try to score by crossing a line.

There also are organized field events that include competitions to see who can throw a disk the farthest or who can keep it in the air the longest.

One of the earliest games invented is called Guts, according to Wham-O, the company that makes Frisbees. Two five-member teams try to throw a disk at each other at such speed that it cannot be caught.

Noncompetitive, freewheeling "Berkeley Frisbee" is like "talking George Washington; it's history," said Dan Roddick, a Wham-O publicist and president of the World Flying Disc Federation.

"It's very difficult anymore to find a college that does not have at least one Ultimate club," Roddick said. "And it's getting easier and easier to find disk golf courses."

Gangloff is serious about his sport. The license plate on his truck reads "DISCMON." His T-shirt says "It's a Dog Eat Disc World" beneath a cartoon of a Frisbee-eating dog.

He belongs to a professional disk golf players association that boasts more than 2,000 active members. He said he wins about $2,000 a year in prize money, helping him cover travel expenses.

Prize money on the 174-tournament circuit this year is expected to hit $250,000, according to Darrell Lynn, the association's paid staff director.