Barite mining was a solid customer of the Yosemite Valley railroad, the National Lead Company shipped many tons of their barite product out of the Merced canyon over the Yosemite Valley railroad. Barite was used in oil well drilling to "cool" the drill bits.

In 1944 National Lead had $360,820 invested in the operations in and near El Portal. Also, National Lead had thirty men employed in working the mine and refining plant. The railroad was hauling 2,800 tons of a finished product every month. This translates to a minimum of 12 cars per week. Plans to increase production to 4,000 tons per month were being considered when the "hearings for abandonment" of the Yosemite Valley railroad were scheduled.

During the so called abandonment hearings, Mr. W. L. Heater, Pacific Coast manager of the Baroid Division of the National Lead company made a very strong protest not to abandon the railroad. He presented figures and arguments supporting position to keep the railroad in operation. Nevertheless, the railroad was allowed to abandon and the shipment of baroids was forced to use the more expensive motor truck.