In May 1898, the West Side Flume & Lumber Company was formed when William H. Crocker, Henry J. Crocker, Andre Poniatowski, Thomas Bullock and Charles Gardner bought 55,000 acres of timber just outside of present day Tuolumne.  A small mill was constructed and a railroad stretched out 10 miles east into the woods. In 1900 the West Side Flume & Lumber Co. incorporated their railroad as a common carrier, the Hetch Hetchy and Yosemite Valley hoping to offer passenger service to the Hetch Hetchy valley and on to Yosemite National Park. Passenger trains were operated twice weekly and later three times weekly. Ridership on the line was low with the primary riders being employees of the company. In 1903 the operation was sold to W. R. Thorsten of Michigan and the corporate name was shortened to the West Side Lumber Co. In 1904 the railroad gave up on passenger service and focused on its growing lumber business.

During West Side's heyday the mainline stretched some 72 miles with nearly 250 miles of spurs, 4 major trestles, and put out over 40 million board of feet in one year. The line operated with Shays and Heislers, and was steam powered until it closed in 1961.

When the summer logging season ended in the fall of 1960 equipment was positioned in expectation of another season starting in the spring. Empty log cars were left in the woods, and the engines recieved normal winter maintenance. Then rather suddenly, the company announced that it would be cheaper to use contract trucks to haul the logs. On June 6 and 7, 1961 two trains were run into the woods to haul the empties to the mill yard and sidings near Tuolumne, and the railroad was put on standby, to see how well the trucks worked. The logging railroad never ran again.

Most of these pictures were taken during 1960, the last season of regular operation.