It was a night from a Christmas card: snow thick on the trees and still falling, the city quiet before morning's struggle with the new winter storm. In a mountain home just beyond the city, children gathered with their parents and three travelers, and together they made a kind of history.

The vistors were from the Soviet Union, and while many Russians have passed through Colorado, seldom has this area seen an exchange quite like the one that occurred here at the initiative of members of Congress and their Soviet opposite numbers.

In four homes in Denver and the outlaying mountain community, gatherings were toasting and talking and listening last Monday night. In all, there were five membrs of the Supreme Soviet, two highly placed advisers and the political consul from the Soviet embassy in Washington.

Their dialogue with Americans was without benefit of long tables, giant delegations or fanfare. At the snowbound home of local entrepreneurs Ann and Michael Moore in Evergreen were Vladimir Kudryavtsev, 76, a Supreme Soviet member and political observer for Izvestia, the official Sovert newspaper, Igor Mikhaylov, an expert on U.S. affairs at the Soviet Academy of Sciences; Dimitri Chetvarikov, political consul; two other local cuples, and the Americans' six children.

After the gathering said grace, which ended with a chorused "Amen," it was time for conversation as mellow as the setting: logs burning in a massive stone fireplace, giant plants everywhere, and a bounty of home-made or organically grown food.

Is it true, Moore asked eventually, that the Soviet Union produces more oil then it needs, that it exports a portion of it?

Yes, Kudryavtsev said. In fact, some time ago, there were discussions with the United States about a mutual trade agreement. The United States was to purchase Soviet oil, and the Russians would buy a guaranteed amount of grain. But, the delegate said, the deal collapsed because at the time, the United States wanted to pay a price below the world market rate for oil.

This prompted one of the American women, Dag Langberg -- a Latvian native who is now a U.S. citizen and was at the winner with her husband, an American Jew --to laugh and exclaim: "Ask them now!" The comment brought applause and more laughter.

Michael Moore asked about Jews in the Soviet Union. Why is it they cannot emigrate?

Many have been allowed to emigrate, the delegates replied, adding some have been denied exit visas for national security reasons or because other members of the applicants' family have requested that a visa not be granted.

The Soviet visitors said they cannot understand why the United Sates attempts to interfere with their internal policies, since their country does not insist that the United Sates change its practices with regard to blacks or other groups before the two countries do business.

While the Americans were not completely satisfied with their Soviet guests' responses, they seemed touched by the symbolism of their presence and by moments of spontaniety, such as a rueful account by Chetvarikov of this troubles getting gasoline in Philadelphia during the shortage.

The dinners here came at the end of the Soviets' 10-day U.S. tour. Earlier, they had visited members of Congress in Washington and attended a town meeting in St. Louis.

They came here at the invitation of Rep. Tim Wirth (D-Colo.), who had been part of a delegation of 17 congressmen who visited the Soviet Union last April for discussions with high-level officials there. After that trip, Wirth and Rep. Richard Gephardt (D-Mo.) suggested that contact between the leadership of the two superpowers could be broadened in an informal way.

"The stakes are enormous -- ultimately the survival of mankind and civilization as we know it," Wirth said.

In the Soviet Union, Wirth said, he learned that the Soviets fear Americans as we fear them, that they view us as aggressors in the arms race, that they mistrust us and neither side understands the other's economic problems.

Cooperation could bring the two countries greater security, scientific and technical knowledge, and trade benefits, Wirth said.

One result of the current visit is a plan to send a delegation from Colorado to the Soviet Union next spring to discuss energy issues, including oil and coal mining, as well as banking and agriculture, Wirth said.

Wirth learned that the Soviets had decided to accept the congressmen's invitation to visit just 10 days before they arrived. Firms such as IBM and Beatrice Foods agreed to pick up the tab for breakfasts or receptions for the Soviet delegates. An itinerary was arranged, and families were contacted about dinners at their homes.

The Colorado visit started with a breakfast at the Brown Palace Hotel last Monday for the Soviets and more than 100 American business and government representatives.

While it was billed as a meeting to talk about agriculture, it was not agriculture that interested those who questioned Sergei Medunov, the head of the delegation. Medunov is a member of the party Central Committee and an important agriculture official in the Soviet Union.

But he had barely finished his pitch for the strategic arms limitation treaty (SALT II) and applauded the goodwill efforts behind the trip here, when Medunov found himself fielding questions on such prickly issues as why Jews were not being released from the Soviet Union, what his country could do to help free the hostages in Iran, and the Soviet military buildup. He responded carefully, stressing cooperation and stressing the importance of the SALT pact.

After the breakfast, the group toured a dairy in Boulder and lunched with the management of the Ball Aerospace Systems Division. In the afternoon, they toured a turkey processing plant in nearby Longmont.

Later, they met with the president of the University of Colorado and visited the National Center for Atmospheric Research, where Soviet scientists frequently participate in exchange programs. Then they went out into the snow to dinner in American homes.