Somewhere out in the deep snow of the Salmon River Mountains, a small group of schoolchildren is preparing for a formidable test of endurance.

The test will come Feb. 2 when all eight children from the one-room schoolhouse here strap on their crosscountry skis and race all two children from the schoolhouse in neighboring Big Creek to the top of a 7,605-foot-high mountain pass named Profile Gap.

The two tiny communities, cut off from the outside world during the winter, lie on either side of the pass. They are without television or telephones and when they are snowed in, access to supplies is only possible via ski-equipped planes or by snowmobiles, which occasionally make the hazardous 69-mile trip from the nearest paved highway.

Bill Erickson, the small, burly teacher who runs the Yellow Pine school, has been writing letters to the state's major paper, The Idaho Statesman, outlining plans for the race. His last letter this week, which got out with the ski plane, said that the children, aged 6 to 15, are practicing three to six miles a day for the grueling 10-mile contest.

Erickson, a veteran skier, described the mostly uphill course as "very difficult from the standpoint of endurance." Most of the children, in fact, had never been on skis until Erickson proposed staging the race as a means of "relieving the boredom" of the long winter months.

His suggestion won the immediate backing of the local school district and of the hardy band of gold and silver miners, cattle ranchers and outfitters for bear and deer hunts who make their home inthe two villages. Almost the entire population of the communities is engaged in helping prepare for the race and for the huge banquet for the children after it.

There have been a few letters to the Statesman protesting the race, one claiming, for example that it is a form of child abuse. But that suggestion has been rejected by the parents of the children, most of whom will stand guard along the route during the contest.

Said Erickson in one letter, "This is the kind of test of will that the children will always remember.

"The dark green of the firs and pines in the cold, white snow really invigorates the spirit," he wrote. "The only sounds you hear are the Clark's Nutcracker, Stellar's Jay, Juncos, the swirling of mountain streams and the swish-swishing of your skis."

Erickson said that he took time out on Christmas Day to ski the route himself with two of his pupils to test conditions. "They were so perfect," he wrote, "that we skied over the gap and down on into Big Creek, a distance of 24 miles. It took six hours to cover it one way."

Just 16 months ago, the 36-year old Erickson had a comfortable job at an affluent school in the Minneapolis subrurbs. He took a leave of absence from Rosemont Middleschoo, where he taught life sciences to the 6th and 7th grades, to try his hand at the solitary life.

He could hardly have chosen a more isolated position. But teaching grades one throuh eight at Yellow Pine (population 60) in the aging, whiteframed schoolhouse, is actually a step upward for him.

His first teaching job in Idaho was at rival Big Creek, population 16.

"It sure beats driving to work in the city," he said. "I get the mountains, I get to ski to work, and I am even my own janitor. I sit by the wood-burning stove in the school at night and hear the owls hoot and I think how lucky I am."

Erickson gets $13,700 to teach in Yellow Pine. The school, (a sign outside modestly dubs it "the University of Yellow Pine") had been closed since 1974 when the population of the village dwindled to almost nothing. But increased mining activity in the region, plus Idaho's populaiton boom, has brough more and more families to the area.

The people of Yellow Pine welcomed Erickson by renovating and furnishing a rent-free house for him, his wife Peg, and their two children. The townspeople also cleaned out the school, paid for new textbooks and even polished the school's 250-pound brass bell which once" pealed out aboard the USS Carson City.

After the ski race was announced, the villagers made and sold Christmas wreaths to pay for sweatshirts for the school team. Other residents volunteered to stand -- on skis or snowmobiles -- along the course of the race, whicl follows much of the East Fork of the Salmon River.

"I want my dad to be proud of me," wrote Russell Marks, 15, the oldest child in the race. He is the son of the owner of the Yellow Pine Lodge. "I have never skied before in my life but I will be doing my best to win," he said.

"It will be an adventure all of us will look back on when we are grown up and we will ask ourselves, did it really happen?"