Mormon Island, situated where the North and South Forks of the American River join on the route from Sutter's Fort to his sawmill at Coloma, was one of the earliest mining camps set up after the discovery of gold at Sutter's Mill.
Six weeks after the initial discovery of gold, a small group of Mormons was mining gold at Mormon Island. By summer of 1848, Mormon Island had over a hundred men. Samuel Brannan, the "Spiritual Guide and director for the Mormon population of New Helvetia and other districts of California" opened a store. For quite some time, Brannan required the miners to tithe by giving one-tenth of their earnings, to the Mormon Church.
The camp was called Mormon Island because the early miners cut a channel across one edge of the gravel bar there, forming a small island. The town quickly outgrew the small gravel bar.
Ad from April 28, 1849, Placer Times.
Daily Alta California, July 24, 1851
SACRAMENTO INTELLIGENCE
We were furnished with the Sacramento papers of yesterday by Freeman & Co.
They contain not an item of news.
We notice the assembling of a Miner's Convention at Mormon Island for the purpose of adopting measures protective of mining interests on the American river. We propose to publish the proceedings tomorrow.
Mormon Island was a natural stopping point between Sutter's Fort and Coloma; by 1850, two stage lines operated. The first ran from Sacramento to Coloma, stopping at Mormon Island. The other ran from Sacramento to Mormon Island and back. The town had become one of the main communities of the Mother Lode. In 1851, a post office was established. By 1853, the population of the town was about 2,500, and by 1855, four hotels, seven saloons and about fifteen other businesses flourished.
June 8, 1888, Sacramento Daily Union
Trout in the American.
There seems to have been no hydraulic mining on the tributaries of the South Fork of the American river for the past several years, and the stream has become remarkably clear as far down as Mormon Island. Chris Ecklon and a party went out fishing a few days ago in the neighborhood of Salmon Falls, and found excellent sport in trout fishing. The speckled beauties were pulled in large number with fly hooks. The American seems to get all its slickens from the North Fork, which joins the South Fork just above the Folsom Prison.