The scene was Troublesome Gulch, near Evergreen, Colo., in a stone-and-log cabin on a dirt road leading up into the Rockies, an elk hide on the wall, a crackling fire. The event was Gary Hart's announcement of noncandidacy for senator in 1986, and the lingo was in tune with the site. "Does that mean I'm making some announcment about '88? Nope. Does it mean I have an interest in being president? Yep." Not far down the road is high-tech metro Denver, its nearly 2 million people spread out over the flat plains beneath the Front Range; within 40 minutes of Mr. Hart's cabin is Stapleton Airport, from which a presidential candidate can easily fly anywhere in the United States in a few hours.

So now, with Edward Kennedy out of the race, is Mr. Hart the front-runner? "I am not in that position," said Mr. Hart, and surely his answer is entitled to respect. He may lead in current polls, but only in a field of little-known candidates in their forties and a 53-year-old governor who seems reluctant to run. As for Mr. Hart, he is beginning his 12th year of service in the Senate amid talk that this year he is going to play a major role in forging a Democratic alternative to President Reagan's budget.

That's welcome news, because he and his Democratic colleagues have been far less successful than House Democrats at this. It would also be useful for voters in 1988, if he runs, to have some evidence of how Mr. Hart exercises leadership. He has done some intelligent and useful work in the Senate, but his record so far doesn't tell you much about his ability to lead.

Meanwhile, back at Troublesome Gulch, the questions were all about positioning. Is Mr. Hart still a new-ideas Democrat, or is he now traditional? Is he an "outsider and candidate for change"? How significant was his lunch last week with Lane Kirkland? What does it mean that the author of 1983's "A New Democracy" may call his new book "America Can Win"?

These questions miss the points they seek to make, and make another. For all his specific stands on issues, Mr. Hart campaigned in 1984 more as a symbol than on substance. He stressed his affinity for a generation and a region. He won his greatest victories in the few weeks after his 16 percent second- place finish in the Iowa caucuses made him a national figure, even though voters knew little about him.

Now he must run over a much longer time under more extended scrutiny, aware of the risk that "another Gary Hart" will overtake him. If he is not front-runner, he is at least a runner to be closely watched. Ignore the mood music and the elk hide, and watch what he does. The useful question is not where candidate Hart chooses to position himself, but where the stands and the initiatives Sen. Hart takes on real-life issues in the Senate end up positioning him.