The Missouri now took in general a southerly course, and on July 18th they reached a bold clear stream, which was named Dearborn River for the then Secretary of War. They had intended to send back a small party in canoes with despatches, but as they had not met the Snake Indians, and so were uncertain as to their friendliness, it was thought best not to weaken their already small party for hostilities. Lewis decided, however, to send Clark, with three men, in advance to open up communication with these Indians and, if possible, to negotiate for horses. Clark's journey was a failure, for the Indians, alarmed at the firing of a gun, fled into the mountains. The mountains now closed in on the explorers and they camped one night at a place named the Gates of the Rocky Mountains. "For five and three-quarter miles these rocks rise perpendicularly from the water's edge to the height of nearly twelve hundred feet. They are composed of black granite near the base, but ... we suppose the upper part to be flint of a yellowish brown and cream color. Nothing can be imagined more tremendous than the frowning blackness of these rocks, which project over the river and threaten us with destruction.... For the first three miles there is not a spot, except one of a few yards, in which a man could stand between the water and the towering perpendicular of the mountains." On July 25th Clark, who was in advance, reached the three forks of the Missouri, where he had to camp, his party worn out, their feet full of prickly pear needles and Chaboneau unable to go farther. The forks were all clear pebbly streams, discharging large amounts of water. The southeast fork was named Gallatin, the middle Madison, and the southwest Jefferson, the latter two, of equal size, being larger branches than the Gallatin. At the three forks Sacajawea, the wife of Chaboneau, was encamped five years before, when the Minnetarees of Knife River attacked the Snakes, killed about a dozen and made prisoners of her and others of her tribe. Strangely enough Chaboneau nearly lost his life crossing the Madison, where Clark saved him from drowning. Lewis was struck with the seeming indifference of the Snake woman on her return to the spot and her own country. The party followed Jefferson River, their journey being marked by the killing of a panther seven and a half feet long, and the overturning of a canoe, injuring one of the party, Whitehouse, losing some articles, and wetting others, but the all-important powder was so well packed that it remained dry.