Easy. Semyon Dezhnev in OTL discovered the Bering Strait and rounded it , but OTL, his discovery was forgotten because the Chkchis were hostile and there was no money in trading with them. ITTL, Dezhnev's party misses the Bering Strait because of fog, sea ice and adverse currents and goes on to sail along the North Shore of Alaska's Seward Peninsula to the Kobuk River, There, he discovers Innuits who will trade with him and gets furs and Walrus and Narwahl tusks. Going further up the Kobuk River to it's head of navigation, he portages to the Koyakuk River, travels down the Koyakuk to the Yukon and follows the Yukon South to the Pacific. He then follows the coast North to where hit is familiar and then back along the Chukchi Coast of Asia, this time discovering the Anadyr river and a faster wa rive route back to Yakutsk.
Subsequent explorations over the next 50 years follow the Yukon to it's sources and portage to the Deh Cho River which ITTL would be known as the Mackenzie River, finally reaching the West shore of Hudson's Bay at Chesterfield Inlet in 1705. This is well North of the furthest North Hudson's Bay Company post at Chruchill. Well before this (1660), the Chilkoot Pass has been discovered to the Inside Passage, which is readily traveled by small boat all the way to the head of Puget Sound. Russian posts follow by 1700 all the way to Puget Sound and by 1720 uthrough the Columbia Basin, accessed by portage from Puget Sound and the Rocky Mountain Trench from the Yukon and the Deh Cho Basins.
And small boats can travel the Pacific Coast all the way down to San Diego Bay, so that by the time Peter the Great is thinking of a pacific navy for Russia, Russia already has aan arc of outposts along the Pacific Coast and deep into North America, trancollecting and transporting furs, as well as Eastern nOrthodox missionaries. ITTL, somewhere along the line, they would bump into the Spanish, French and English. But the Russians would have a clear run from 1554 at what stayed unexplored territory until the 1789s ITTL.