An independent, federal California Republic. California has both English and Spanish as its official languages and is closely allied with Republic of Texas, with a defense pact against the US and Mexico and a trade agreement, allowing California access to the Gulf trade routes and Texas access to the Pacific ones.
What happened to Sonora's borders?? And did the Mormons ever make it to the Great Salt Lake?
I made this map years ago but I think the idea was that northern Mexico rather than being ceded to the United States became independent as California. Sonora's borders were... simplified a little with the northwest being assigned to Arizona to give it sea access. The Mormons did make it to the Great Salt Lake and form the majority of the population of Colorado Territory (who's capital, Ide is named after the first president of California William B Ide).
Are the Mormons as abused as they were in OTL?
I'd think so. Enough for them to leave the US for the desert around the Great Salt Lake and then when the area came under Californian control the area was organised as Colorado Territory, depriving the Mormons of self-government as the territorial government is mostly comprised of failed politicians from Monterey and the coastal cities.