In 1857 a group of 11 English families travelled from Salt Lake Valley, Utah to San Bernardino, California. They were seceding from the Mormon Church. Captain James Singleton was listed among the heads of the families. He is listed (age 46) in the 1860 census for San Bernardino, CA, along with Ann, 45, and William, 24.
I have no connection with this Singleton family other than that my gg grandfather was in the same wagon train, but if you're interested, I will give you what little I have on them. Likewise, if you have any information about their migration from Utah to Califoria, I'd like to hear from you.