What are you refering to? Vitus Bering, a danish naval officer in russian employment, found Alaska in 1741, after looking for it since 1725. You should read this: Orcutt William Frost: Bering: The Russian Discovery of America, Pacific Northwest Quarterly 86, No. 1, Winter, 2003.

Besides, the russian explorer Grigori Iwanowitsch Schelichow, reached [Kodiak Island in 1783] (http://de.wikipedia.org/wiki/Kodiak-Insel) . So they did discover Alaska to answer the question.

Edit: Sorry for the Wiki article, but it might peak your interest, since it would appear you did not know this. http://de.wikipedia.org/wiki/Alaska_Purchase and in english http://en.wikipedia.org/wiki/Alaska_Purchase, sorry about the german article.

Oh, I see, Russia didn't control east 'Siberia' until after America had already been discovered