The most challenging portion of the construction of the Fernley & Lassen Railroad came in the summer and fall of 1913. From Fernley, Nevada to Susanville there were no major obstacles. Everything changed with the terrain of the Susan River Canyon which would require the construction of numerous trestles to cross the Susan River as well as two tunnels.
In June 1913 work began on Tunnel No. 1 which required heavy blasting. It even required locating the construction camp out of harms way. The workmen, of course, were warned to seek a safe place before a blast was discharged. William Denham took the advice and positioned himself across the river some two hundred yards distance. Above him was a rocky ledge, and the force of the blast was so great that a rock was thrown passing Denham, but striking the ledge above him, causing it to loosen. A mass of rock rolled onto Denham, Initial reports had Denham’s leg horribly mangled and broken, but actually he was only severely bruised with no broken bones.