Russia had a settlement in California (Fort Ross), but I don't know if they ever claimed the whole state or parts of it.
https://en.wikipedia.org/wiki/Fort_Ross
Russian explorers and settlers continued to establish trading posts in Alaska, the Aleutian Islands, British Columbia, Washington, Oregon and as far south as Fort Ross in northern California. Fort Ross, some 50 miles north of San Francisco, was founded in 1812 and closed in 1841. El Presidio Real de Sonoma, or Sonoma Barracks, was established at Sonoma, California in 1836 by Mariano Guadalupe Vallejo (the "Commandante-General of the Northern Frontier of Alta California") as a part of Mexico's strategy to halt Russian incursions into the region.
https://en.wikipedia.org/wiki/Russian_colonization_of_the_Americas
I get a little confused over the year 1846.
It was the year of the Oregon Treaty, but this was a treaty between USA and UK, I don't think Russia was involved in it.
https://en.wikipedia.org/wiki/Oregon_Treaty
As far as I can see, the only territory claimed by Russia at this time was Alaska. But Alaska was Russian territory from 1733 to 1867, so the date 1846 doesn't make sense.
https://en.wikipedia.org/wiki/Russian_Alaska
