From the posting in the park:

“Once a Small Bustling Town

In 1948 Joseph L. Folsom purchased the grant of 35,521 acres once owned by William Leidesdorff, Vise Consul of the United States. When J. L. Folsom purchased the grant, the gold rush was in full swing and Negro Bar was bustling with activity.

Negro Bar, once located along the river at the current townsite of Folsom and extending a mile down stream was mined by African Americans in 1849. The small community had a store, two hotels and numerous houses by 1850. In 1851 the town had about 700 people. By 1855 the town of Folsom was established replacing the small town of Negro Bar.

Today the remains of Negro bar are few. The actual site location varies in the literature, while a few old letters reveal life as it once was across the river.”