The Grand Targhee Ski Resort plans a $27.3 million expansion, including four new lifts and nearly 1,000 new hotel rooms and condominiums, aimed at accommodating more than 350,000 skiers each winter.

The ambitious expansion plan unveiled Thursday night startled some Teton Valley residents. They say Mory Bergmeyer's latest proposal for the Alta, Wyo., resort is much larger than they expected."I'm disappointed that after a year and a half of controversy, the resort has grown," said Mike Whitfield of Driggs, a member of Citizens for Teton Valley, a group opposing Grand Targhee expansion.

The U.S. Forest Service released Grand Targhee's expansion plans at a crowded public meeting. It also announced its schedule for an 18-month review of the proposal.

Key points of the expansion plan include:

- Doubling the lift system from four to eight units. The expanded lifts would handle nearly 6,500 skiers a day. The current network accommodates a little more than 1,900 skiers a day.

- - A total of 1,159 hotel rooms, condominiums and single-family homes at the resort, providing overnight accommodations for more than 2,500 skiers. Currently, the resort has overnight space for 309 skiers in its 96 rooms.

About 100,000 skiers now visit Grand Targhee each winter, but that could more than triple by the time the expansion is complete if the plan's projections are realized.

Numbers like that worry Whitfield, who contends the growth is being driven by real estate development rather than the ski market.

"I think this scale of development takes Targhee away from the people who have enjoyed it all these years," he said.

But a consultant for Grand Targhee emphasized that the expansion plan will be implemented over a number of years.

"I think you have to realize it's not an overnight thing," said Darcy Alexander of Ecosign, a ski area planning company based in Whistler, B.C.

Part of the gradual growth will be in the Teton Valley. Eventually, developers expect 40 percent of skiers to stay overnight at the resort and 35 percent to stay elsewhere in the valley. The remainder would be day skiers who now account for most of Grand Targhee's business.

The time-share condos and single-family homes would have to be developed on private land, rather than Targhee National Forest acreage. That would require a land swap to free up at least 100 acres at the resort for private development, Alexander said.

However, the resort probably will not need the 270 acres of land it has sought in earlier land-exchange talks. "I believe it will be significantly less than that," Alexander said.

The Forest Service's review of the expansion is just beginning. The agency plans to conduct hearings in Idaho Falls, Driggs and Jackson, Wyo., in early January to discuss the proposal. It hopes to release a draft environmental impact statement on the project by Oct. 1, and a final review by May 1992.

Two local committees will get a voice in the expansion issue. Community leaders will review the environmental impact statement process, while the Economic Development Council appointed by city and county officials will be asked to develop a community alternative to Bergmeyer's plan, said Lynn Ballard of the Targhee's Teton Basin Ranger District.

Through community meetings, polls or a questionnaire, the council will try to gauge local support for expansion. Council member Steven Leibler of Victor called it an attempt to head off more of the "antagonistic bickering" that has surrounded the Grand Targhee expansion issue.

Forest Service officials also hope the lengthy review will help defuse the expansion controversy.

"I see a lot of mistrust," said Bob Williams, the Targhee National Forest's recreation branch chief. "I believe now would be a good time to put all that stuff behind us."