It’s winter, the wind is howling, the chill is to the bone, and the muddy spaces in the Manuel F. Correllus State Forest’s Barnes Road lot are packed with cars. It’s Sunday morning, and a dozen or so people are congregating, readying themselves for a procession into the hidden depths. They are devotees of Frisbee Golf. Frolfers.

They are here, no matter the weather, to play the leisure sport called disc golf, Frisbee golf or frolf. It mixes the concept of standard golf - the goal is to hit the target with as few shots as possible - with the art of throwing a Frisbee. There is skill involved, but the trial and error factor can be quite amusing.

Frisbee golf offers exercise, fun and game - and it's free to play here on the Island. All you need are special Frisbee discs, sneakers and a throwing arm. Like its more country club counterpart, Frisbee golf seems to be ever-growing in popularity, with some players in it for the exercise, some for the competition.

Here on the Island, an informal league of 10 to 15 players comes together on Sunday mornings and Tuesday afternoons to battle over a coveted, make-shift trophy for the best round. Whoever has the lowest score that round - that is, whoever gets around the 18-hole Martha's Vineyard Riverhead Field Disc Golf Course using the fewest throws - gets to autograph the Frisbee trophy. That's bragging rights, especially if your name is there multiple times.

The course nestled inside the state forest is not a secret - it's been there for ten years - but it doesn't seem to be well known around the Island. Perhaps that's because it blends into the landscape - well, except for those strategically scattered, funny-looking chain-link baskets on poles, the "holes."

On this frigid March Sunday morning, the group of 12 paired off into teams of two. Before they ventured onto the course, to battle each other and the elements, they huddled together discussing tactics. Each had to overcome the hurdle of throwing little Frisbees into big wind gusts.

Fourteen-year-old player Max Conley summed up the situation: "In this kind of wind some of [the discs] are going to go backwards."

He wasn't wrong. Even though the seasoned throwers use unique styles and various discs - most players come with several in their frolf bag - each got the same result: boomeranging Frisbees. Frisbees going in exactly the opposite direction they were supposed to go.

The players all were shocked and amused. Veteran Jake Gifford geared up to throw his disc so it would fly straight, directly to the basket. Instead, it turned right, and he was baffled. "That disc has never gone [to the] right ever – it's the most stable disc," he said, shaking his head.

These players have done this course over and over again, but, as Danny Kaeka said, incredibly, the game is never played the same. Each shot will be different, no matter how many times you throw the same disc. It makes the game that much more interesting.

"The more you play, the harder it gets," said John Vermynck.

"You start thinking about it too much," Daryl Kaeka Jr. added.

It can be as much a mind game as a skill game, making Frisbee golf - much like that other golf game - not just fun, but addictive.

Attendance is not even daunted by snow. "You know something's wrong with me when my back's killing me and it's snowing out and I'm still here," laughed Mr. Vermynck.

The Island course was built in 1997. It was founded by Seamus Scanlon, John Tate and Eric Brown and crafted with the help of the Kaeka brothers - Dennis, Daryl, Dwight and Danny.

"I started it because it was wintertime and there was nothing to do," Mr. Scanlon said. "What choices do we have for free, low-impact activities?"

Since then the forest course has been well-worn. Many Frisbee discs have been lost among its trees and bushes.

On this day, Dwight Kaeka uses his "thumber shot" to compensate for the wind. It was quite the sight: the Frisbee soared high, only to flip over as it fell to the ground - well, almost to the ground. His disc landed among the branches of a bare tree.

A regular player, Mr. Kaeka came prepared for this kind of thing. "Standard Frisbee equipment," he said, revealing a baseball, which he threw to free the Frisbee.

The course is unusual in that it is on state land; most other American courses are on federal land. The construction of the course was approved by the state forest ranger so long as the course wasn't obtrusive. That is why you won't find any sign signifying the presence of the course.

Each hole here is considered a par three, with a range of between 175 to 470 feet. At each hole, there are white, blue and red tees: the blue "expert" tees are farthest away from the basket, creating the most difficulty; the red "family" tees are closer to the basket, allowing for more family fun, especially for younger children. Most people play from the white "intermediate" tees, aiming for a happy medium between challenge and fun.

"The different tees help you improve your longer shots," said regular Jennifer Foxlee. "Since we only have one course, [playing from different tees] makes it a little more challenging."

The average time to play the whole 18-hole course from the white tees is about one and a half hours.

There are hundreds of different Frisbee golf discs, each with properties allowing for the various types of shots. They weigh between 135 and 180 grams, but are denser than a regular Frisbee. Aerodynamically, they are built to be more accurate, versatile, durable and travel farther than other Frisbees.

The frolf long-distance driver provides more length in the shot - it is built to be thrown, not caught. Getting hit with the long distance driver can cause quite the dent.

The putter is more stable, for shots closer to the basket. It looks more like a regular Frisbee.

The multi-purpose or mid-range disc is a hybrid of the long distance driver and the putter.

Technically, you can use just one multi-purpose Frisbee disc to play the whole course (minding that it doesn't get lost or stuck in a tree). But to play the game to its fullest, it helps to have at least one of each disc.

"I usually have about seven Frisbees in my bag," said Ms. Foxlee, displaying a rainbow of different discs, many of them pink.

Rom Wingood pointed out that a Frisbee can look a lot like a bird flying through the air. To track where your disc lands - otherwise you spend a lot of time looking for a disc instead of using it to play the game - brightly colored discs come in handy.

Ms. Foxlee's special Frisbee golf bag is built not only to hold the discs but also to give easy access to them without getting in the way of her throwing.

The winter provides the relative advantage of bare trees, but layers of restrictive winter clothing make the discs harder to throw. Also, wight Kaeka said, "discs don't fly as well [in winter] because they're not as flexible."

The summer provides other obstacles. The forest is more overgrown. Then there are the ticks, always more of an issue in the warmer weather.

Whatever the weather, Dwight Kaeka Jr. advised: "Go play. It's nice to get out and walk around."

Tomorrow the Vineyard will host the Vineyard Social III, a tournament to attract any Frisbee golfer, professional or amateur. It is a great place to meet other Frisbee golf enthusiasts and to check out the competition. The tournament is a New England Flying Disc Association (NEFA) points event. There are four categories: recreational, amateur 2, amateur 1 and pro.

Asked what his goal for the tournament was, Eric Brown said simply: "Not finish last." Others are just looking forward to another round of play.

The Sunday trophy round over, some frolfers have been playing since 8 a.m.; others will play all day until there is no light.

"We're having a blast," said Danny Kaeka, as he headed out again.

The Vineyard Social III tournament is Saturday, March 24. Registration begins at 7:30 a.m., play at 10 a.m. Spectators welcome. For details, call 617-816-7400.