over their toll road to and from the ever-advancing railhead and over the Sierra to the gold and silver mining towns of Nevada. As the railroad advanced, their freight rates with the combined rail and wagon shipments would become much more competitive. The volume of the toll road freight traffic to Nevada was estimated to be about $13,000,000 a year as the Comstock Lode boomed, and getting even part of this freight traffic would help pay for the railroad construction. When the railroad reached Reno, it had the majority of all Nevada freight shipments, and the price of goods in Nevada dropped significantly as the freight charges to Nevada dropped significantly. The rail route over the Sierras followed the general route of the Truckee branch of the California Trail, going east over Donner Pass and down the rugged Truckee River valley. The route over the Sierra had been plotted out by Judah in preliminary surveys before his death in 1863. Judah's deputy, Samuel S. Montague was appointed as Central Pacific's new Chief Engineer, with Lewis M. Clement as Assistant Chief Engineer and Charles Cadwalader as second assistant. To build the new railroad, detailed surveys had to be run that showed where the cuts, fills, trestles, bridges and tunnels would have to be built. Work that was identified as taking a long time was started as soon as its projected track location could be ascertained and work crews, supplies and road work equipment found to be sent ahead. Tunnels, trestles and bridges were nearly all built this way. The spread-out nature of the work resulted in the work being split into two divisions, with L.M. Clement taking the upper division from Blue Cañon to Truckee and Cadwalader taking the lower division from Truckee to the Nevada border. Other assistant engineers were assigned to specific tasks such as building a bridge, tunnel or trestle which was done by the workers under experienced supervisors. In total, the Central Pacific had eleven tunnel projects (Nos. 3 through 13) under construction in the Sierra from 1865 to 1868, with seven tunnels located in a stretch on the east side of Donner Summit. The tunnels were usually built by drilling a series of holes in the tunnel face, filling them with black powder and detonating it to break the rock free. The black powder was provided by the California Powder Works near Santa Cruz, California. These