Backed by friends and lobbyists who charged him nothing, Sen. Mike Gravel (D-Alaska) holds a share of a Colorado resort property that could bring him more than $100,000 in resale income.

Gravel was awarded his share for showing what his partners termed "leadership" in developing a fancy vacation retreat along the ski slopes of Aspen, Colo.

Aspen real-estate salesmen say the property, known there generally as "Mike Gravel's house," could fetch as much as $1.5 million on the resale market in the popular mountain vacation community.

Gravel said he agrees with the estimate of potential resale value, but that there is no intention to sell the place. One of the 12 shares in the partnership is on the market for $37,000.

"I'm into it because I like to ski and it's on the way home to Alaska," Gravel said.

Although Gravel made no secret of his involvement in the project, it did not become common knowledge until last month when the Anchorage Daily News reported details of the financial arrangements of Aspen House's ownership.

Since then, the issue has created a political furor in Alaska involving Gravel, his Democratic primary opponent, Clark Gruening, and the Anchorage newspapers.

Among the original investors, both of whom continue as partners, are two Washington lobbyists who have had close contact with Gravel on energy and land-development legislation affecting Alaska.

Charles L. Fishman and William C. Foster, both attorneys, were personal friends of Gravel's before they became lobbyists and before he invited them into the partnership for $15,000 each.

Both lobbyists joined Gravel in denying that their business partnership in Colorado has had any effect on legislative matters before the U.S. Senate.

"This is a social venture," Gravel said. "I'm not in it to make money. Nobody is busting a leg to make money off of this. In fact, we lost money last year, and this year, and the partners have been assessed extra."

Fishman and Foster were asked into Gravel's partnership after the senator, a real-estate developer before his election in 1968, decided four years ago to build the luxury dwelling in Aspen.

The structure in Snowmass Village, financed by lenders in Alaska, Colorado and Texas, was designed by Gravel as a vacation hideaway for partners and as rental structure when not in use by its owners.

Aspen House has four suites, which each rent for $300 a day during the peak of ski season. The suites include hot tubs, saunas, fireplaces and color televisions, and have attracted such luminaries as Canadian Prime Minister Pierre Elliott Trudeau and wealthy Arabs as guests.

With the $15,000 seed money provided by his friends and partners, Gravel's equity as a general partner has climed to $37,000. His latest financial disclosure filing with the Senate indicates Aspen House is an asset worth more than $100,000.

"I put up nothing, but the design work and the entrepreneurial talent. I love to do that kind of thing. It's therapy. I love it," Gravel said.

"I put up more than $37,000 worth of talent and time. It's worth a damned sight more than that. But I have a liability out of this. Nobody else went on the line. My name is on it for $700,000; my partners' is on it for $65,000."

The business connection with lobbyists whose job is to win senatorial hearts and minds has become a part of an angry feud between Gravel, primary opponent Gruening and The Anchorage Daily News.

Gruening, a young Anchorage attorney, is the grandson of the late Sen. Ernest Gruening. Gravel won his way into the Senate by defeating the elder Gruening in the state's 1967 Democratic primary.

Gravel has accused the Clark Gruening campaign of "feeding" the Aspen House story to the newspaper, which writer Paul Nussbaum and associate editor Howard Weaver vigorously deny.

After the Gruening campaign issued similar denials, Gravel produced a defector who was flown to Washington to make a television tape in which he alleged that Gruening aides had gathered information on the Colorado property.

The Daily News' competition, The Anchorage Times, fanned the fire a bit more with an editorial claiming tha a Gruening assistant had approached the Times with an offer of information about Aspen House, an offer it rejected.

Gravel associates also are suggesting privately that the camp of his bitter rival, Sen. Ted Stevens (R-Alaska), who has endorsed Gruening, has attempted to interest the national press in the story of Aspen House.

In the wake of the News' stories and editorials critical of his private business ties to the lobbyists, Gravel has banned his staff from having any contact with representatives of the paper.

"This whole deal is not over by a long shot," Gravel said. "It became a flap because that kid defected. We put him on TV in the state to get the story out . . . There's nothing wrong with anyone being fed a story, but they lied and the Gruening people lied and the Times blew them out of the tub."

"I get a bad rap because I'm so much a maverick and so independent. I try to be my own man," Gravel said.

Lobbyists Fishman and Foster have had long-time associations with Gravel, and both have contacted him on legislative issues, but apparently with only middling success.

They were paid $77,246 last year by the state to lobby the Alaska position on the land distribution issue. Gravel's recalcitrance torpedoed a state-supported compromise that was worked out in Congress in 1978.

Fishman, also Gravel's private attorney, represents the Westinghouse Corp. on nuclear issues -- usually opposing Gravel. In 1977, at the senator's behest, he was hired by the state to help lobby on the lands bill.

Foster and Gravel have been friends for years, dating back to a time when Foster was an assistant to former senator Bob Bartlett, who died in 1968.

Foster is associated with the Patton, Boggs & Blow law firm here, the state's principal representative on lands legislation. He also has been a lobbyist for industry interests in the Alaska oil and gas pipeline schemes.

Gravel's other associates in the Aspen venture include Alaska political figures, hoteliers and personal friends with little or few political connections.

They include Gravel's other general partner, hotelman-lawyer Mark H. Fleischman of New York City; Robert L. Mitchell, a former Gravel aide who now manages his reelection campaign; William Sheffield of Anchorage, a hotel operator, who is his campaign manager, and James C. Callaway, president of a small oil company in Texas.

"Of course, they're friends," Gravel said. "When I go to Aspen House I want to be among friends. I don't want some turkeys staying in Aspen House."