The trail led from the Missouri across the state of Kansas to the Platte River, then followed this long stream to its head at South Pass on the continental divide. From the South Pass the trail led southwest past Fort Bridger, in southwestern Wyoming, through Echo Canon and over Emigrant pass of the Wasatch Range down to Salt Lake City, which had been founded but a short time before the discovery of gold. West of Salt Lake City the trail skirted the northern shore of the Great Salt Lake, and after passing a low mountain divide in what is now northwestern Utah, reached the head waters of the Humboldt River. Thence the path ran along by this river down to the place where it disappeared in a vast sandy desert known as the sink of the Carson. The Carson River, after the dreary desert was passed, led the emigrants still westward toward a wall of mighty mountains known as the Sierra Nevada. Here Nature seemed to have done her utmost to shut off California, with its fertile valleys and rich gold-fields, from the longing eyes of the emigrants. There are, however, several low places in the range, and through one of these openings, at the head of the Carson River, the travellers gained the western slope of the mountains. Then in good time they reached the mining town of Placerville, and at length Sacramento, the capital of California. [Illustration: FIG. 91.--CHIMNEY ROCK On the old overland trail near the Platte River, western Nebraska] In order that the pony express might make the time required over the two thousand miles, five hundred horses and several hundred men were needed. The stations were placed about ten miles apart and were strongly built so that they might withstand the attacks of the Indians. These stations, nearly two hundred in number, all had to be supplied by means of freight teams, which often hauled hay, grain, and food for the messengers for hundreds of miles. The horses selected for the messengers to ride were the small, sure-footed ponies called mustangs. Through a stretch of ten miles the pony was pushed to its utmost speed, then it was carefully groomed, fed, and rested until the time came to make the return trip. In selecting the riders three things were of great importance: they must be light in weight, must be possessed of great powers of endurance, and also must be brave and resolute. At each station, as the time approached for the express to arrive, the relay horse was saddled and in waiting. As the rider dashed in he jumped from his horse, and with but a moment's rest, threw the saddle-bags containing the letters upon the fresh horse and was off again, riding like the wind. Upon smooth stretches the horses often made twenty miles an hour, but it was quite impossible to maintain this speed over the rocky and rugged portions of the route. Storms and Indian ambuscades often delayed the riders. Sometimes the messenger kept up a running fight with the Indians for miles.