5 o'clock
They were enabled to change horses as near as possible every hour , by telegraphing ahead in the morning , during the day , and often far into the hours of night . Starting from Julesburg early in the morning of the 17th , their first resting place for a few hours at night was Granite Canyon , twenty miles west of Cheyenne , and just at the foot of the pass over the Black Hills . On the 18th , night-fall found them entering St. Mary 's , at the further end of the pass between Rattle Snake Hills and Elk Mountain . It was after 5 o'clock and already dark on the 19th , when the travellers , hurrying with all speed through the gloomy gorge of slate formation leading to the banks of the Green River , found the ford too deep to be ventured before morning . The 20th was a clear cold day very favorable for brisk locomotion , and the bright sun had not quite disappeared behind the Wahsatch Mountains when the Club men , having crossed the Bear River , began to leave the lofty plateau of the Rocky Mountains by the great inclined plane marked by the lines of the Echo and the Weber Rivers on their way to the valley of the Great American Desert . Quitting Castle Rock early on the morning of the 21st , they soon came in sight of the Great Salt Lake , along the northern shores of which they sped all day , taking shelter after night-fall at Terrace , in a miserable log cabin surrounded by piles of drifting sand . The 22d was a terrible day .