Gretchen Bleiler sailed above the lip of the halfpipe Friday morning, spinning, grabbing, frontside, backside, over and over.

She exhibits the grace that sets many top athletes apart from mere mortals, and was one of scores of young men and women taking practice runs through the pipe.

Bleiler, of Aspen, is a top American snowboarder, winner of a silver medal in halfpipe at the Olympics in Torino, Italy, and a perennial power in women's boarding.

She is among the competitors who are automatically qualified for the finals over the weekend. Others compete in the qualifiers that make the U.S. Open truly an open event to which every young snowboarder can at least aspire.

That's the theory. Getting into the Burton U. S. Open is a mix of lottery, achievement and connections.  It also depends in part on luck, as Hannah Teter, gold medal winner in halfpipe at the Torino Olympics, was a shoo-in for the finals until she injured her shoulder during practice at the U.S. Grand Prix at Killington.

"I'll be resting for a few weeks," Teter said Friday.

[R430R, Stratton] devotes much of its Sun Bowl to the U.S. Open, which began in 1982, moved here in 1985 and has been an annual highlight of the season ever since.

The halfpipe is 500 feet long with sides 22 feet high. Decks run its length above the walls, for competitors to walk back to the top, and for spectators to watch from behind a fence.

The U.S. Open runs Monday through Sunday, with the first days set aside for practice and qualifiers for athletes not already invited to the finals. Semi-finals and finals are held through the weekend - 5:15 to 7:45 p.m. Friday March 20 for Quarterpipe, 8:30 a.m. to 3:45 p.m. Saturday for Halfpipe, 8:30 a.m. to 4 p.m. Sunday for Slopestyle and 8:30 a.m. to 3 p.m. Sunday for Junior Jam.

Leslie Glenn of Breckenridge sat on the deck between runs through the halfpipe earlier in the week, and watched other competitors practice .

Later she critiqued photos of the morning runs.

"That's great form," Glenn said of one image. "She went big, good grab, excellent body position."

Glenn is one of the 5.1 million Americans over age 7 who are snowboarders. Unlike most, she competes in big events across the country, most recently in the U.S. Open and the weekend before at the Snowboarding Grand Prix at Killington and another competition at Waterville Valley.

Fifty-seven women competed this week for five spots in the U.S. Open Halfpipe finals reserved for selection through the qualifiers. Glenn did not make the cut, finishing 15th on Thursday.

Kelly Marren of California finished 6th, and is an alternate for the finals with a good chance of competing.

Greg Johnson, Burton U.S. Open competition director, put it this way: "More so than any other event, the U.S. Open can make a career, and that's huge. If you go to the Olympics, you're one of the top two or three riders; if you go to the X Games, you're top 20 anyway. At the U.S. Open, there are qualifiers, pre-qualifiers, semis and finals, and if you do well you instantly make a name for yourself and have a lot of cred."

The U.S. Open remains the premier event in snowboarding for several reasons, Johnson said, including the huge commitment from Jake Burton Carpenter; fundamental creativity in formats, judging and course building; and willingness of organizers to listen to suggestions from judges and riders to make it better each year.

Jake and his wife, Donna Carpenter, the founders of Burton Snowboards, have shared the wealth in many ways over the years. They started a program called Chill in 1995 in Burlington, Vt., to bring snowboarding to youth who otherwise wouldn't have the opportunity. The non-profit learn-to-ride program was a hit, and has continued to expand into new cities and new countries over the past 14 years. Chill has made snowboarding possible for 14,500 kids and this year will serve over 1,800 youths from 14 North American cities, Sydney, Australia, and Innsbruck, Austria.

Johnson said this energy flows through most aspects of snowboarding.

"At the top of the snowboarding halfpipe, it's all positive. The riders talk to each other, very few are off in their own little zone the way ski racers tends to be. They're excited to see good riding from their peers, because they get pushed a little harder. It's competitive but it's anti-competitive in a way too," Johnson said.

"They all want to win, but they all want to win with style and doing their best. That's a huge important part to that scene. If they're on top and see someone else throw down a sick run they'll applaud that and figure out a way to beat it. They talk to each other. They're anxious to see if someone‘s learned a new trick that they don't know," he said.

"One of the really cool things with snowboarding, there's total freedom in your runs because of the way judging is set up. In any other sport, there's either a point value for the tricks or there's a routine. Snowboarding has neither of those, so there's a huge amount of freedom. Riders can be creative, experiment with different runs. If a run scores big they figure out what they can add to it," Johnson said.

"With that freedom comes a certain amount of acceptance from the riders for the judges' subjectivity. Let me put it this way: Snowboarders' sense-of-fairness meter takes a lot to get it out of balance," he said.

Myra Foster of Stratton is a snowboarder who loves the sport and, as she calls them, the kids who are its main practitioners.

"They're really out there for each other. I'm not saying there's no camaraderie in other sports, but more than in other sports there's real camaraderie in snowboarding. They compete together, they travel together, they hang out together, they cheer each other on. It's such a community in a sport where they are essentially competing against each other, but it's not really that way; they're competing to do the best, they want everybody to do well. They're always pushing each other to go higher, to do better, to try something new," Foster said.

See for yourself at the U.S. Open, running through the weekend at Stratton. It's free for spectators.