As part of the California Gold Rush, placer miners explored the San Joaquin River.

A man named Cassady set up a placer mining operation, near where the Temperance Flat Dam was proposed to be built, around 1851.

The settlement was located along the Stockton - Los Angeles Road which allowed travelers to visit by stage and freight wagon.

[4] In 1857, the first county-built jail structure was completed but a prisoner demonstrated it was easily escapable due to poor construction.

County business was conducted in a very informal fashion, with the officers often taking breaks from their work to meet at a saloon.

The building was two stories and contained a courtroom, a jail, as well as offices for the sheriff, assessor, treasurer and clerk.

The most notable structures besides the courthouse were Ira McCray's Oak Hotel, Payne's Exchange Saloon and George Greierson's General Merchandise Store.

[5] The town began its decline when the San Joaquin River flooded on Christmas Eve, 1867, inundating Millerton.