Why did Americans move to California before the gold rush?

Answer 1

They hardly did. In 1845, the non-native population of California numbered no more than 8,000 and most of those were Mexicans and Russians.

One of the reasons Americans did not settle there was the very long and hard journey across deserts and mountains you had to make to get there. And once you got there there was little other activity than a little local ranching. The few coastal settlements were mostly manned by Russians at the time: what harbors there were only opened up to a vast and empty Pacific Ocean with only Russian Alaska and eastern Siberia as more or less 'nearby' destinations. The Mexicans dominated most other activities, since Mexico was the only viable in- and export market for any economic activity further inland.