The Russians aren't coming . . . they're here.

The principal participants in the U.S.-Soviet summit arrived to an enthusiastic welcome Thursday night that included a red-carpet greeting from Wyoming's governor and placard-waving schoolchildren.Secretary of State James A. Baker III and Soviet Foreign Minister Eduard A. Shevardnadze Friday posed outside Jackson Lake Lodge and watched two moose grazing just below the terrace. After opening remarks, Baker and Shevardnadze adjourned to a separate room for one-on-one talks. Their teams then got to work at long tables with the Soviets on one side and Americans on the other.

The view afforded the two diplomats and their parties is one of mountain majesty blazing with autumn colors of red, orange and yellow. The setting contrasts sharply with the seriousness surrounding this latest phase of superpower bargaining. Both American and Soviet sides expressed optimism that agreement will be reached on several topics scheduled for discussion. Baker and Shevardnadze also took the unusual step of announcing they were prepared to give a "time frame" for a summit between President Bush and Soviet President Mikhail S. Gorbachev.

Both delegations also took time to hold late-night "background" briefings with reporters to position themselves for what may be some tough bargaining. Refusing to outline specific areas of disagreement, officials from both countries expressed their desire to clarify their positions in light of a detailed and technical letter Gorbachev had delivered to Bush on Thursday.

The Gorbachev letter, while sparking considerable curiosity among the press, was discussed at length by Baker and Shevardnadze during the flight to Wyoming. The two talked nose-to-nose for nearly two hours, according to witnesses aboard Baker's DC-9.

Wyoming Gov. Mike Evans was the official greeter, welcoming the Soviet delegation to his state. The Soviets had to wait until morning to glimpse their surroundings because the Washington entourage arrived after dark.

Sessions among the five working groups were held in the morning and in the afternoon. The working groups will continue Saturday as needed. Saturday night, the Bakers are throwing a Western-style barbecue for the Shevardnadzes.

Before the U.S. and Soviet delegations arrived, residents of Jackson and the surrounding area gave a collective shrug to the diplomatic activity in their midst. Except for the arrival of the advance teams from the U.S. State Department and Soviet Foreign Ministry - along with several hundred journalists - most Jackson Hole shopkeepers appeared more concerned with the windup of summer and the impending arrival of ski season in two months.

Downtown Jackson is littered with "Peace and Freedom" fliers written in both English and Russian. About the only other notice of the summit are the T-shirts for sale, picturing Shevardnadze and Baker on opposite sides of the ever-present Jackson Moose (the local mascot). And to ensure the Russians will appreciate American capitalism, the shirts retail for a hefty $13.50.

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(Additional information)

A chronology

-March 7--Vienna, Austria: Baker and Shevardnadze held brief introductory meetings on margins of opening of Conventional Forces in Europe negotiations.

-May 10-11-Moscow: The two held first full minsterial meetings with working groups; they agreed to resume bilateral arms-control talks and set new cycle of regional experts meetings.

-July 29-Paris: Met on eve of opening of conference on Cambodia.

-Sept. 22-23-Jackson, Wyo.: Second full ministerial meeting accompanied by working groups.