Wind River Shoshone informants relate the itineraries of buffalo-hunting parties northward into the Big Horn Basin. The fall and spring buffalo hunts were said to have taken place in the region of Thermopolis, Wyoming, and as far north as Cody and Greybull, Wyoming. The region east of the Big Horn Mountains was thought by informants to have been occasionally visited, but was acknowledged as the hunting grounds of hostile tribes. The presence of a "mixed party of Shoshone and Flatheads" in the Big Horn Mountains was noted by the westward-bound Astoria party in 1811 (Irving, 1890, p. 196) and indicates some early penetration of the area, although the presence of Flathead Indians suggests that the party had entered the area via Idaho and Montana and not from Green River. However, pre-reservation historical data show that before the 1840's the Eastern Shoshone largely restricted their buffalo hunting to the region west of the Continental Divide and sporadically penetrated the Wind River and Big Horn basins only after the buffalo disappeared from the country beyond the Rockies. Their entry into the eastern buffalo range became more frequent in the 1850's, but it by no means constituted an exclusive monopoly on lands there. They depended upon their numbers for protection and were forced to compete with other tribes for the right to hunt on the land. Their hunting excursions were in the nature of forays and were unsuccessful in some years. They enjoyed security and some assurance of success in the hunt only after they had been placed under the protection of Federal troops and the Crow had been placed on reservations. That the center of Shoshone occupancy lay west of the Continental Divide was affirmed by Chief Washakie. Agent Head wrote in 1867 (1868, p. 186): Washakee said that the country east from the Wind river mountains, to the settled portions of eastern Nebraska and Kansas, had always been claimed by four principal Indian tribes--the Sioux, Arapahoes, Cheyennes, and Crows. Further evidence that the valleys of the Big Horn and Wind rivers were used only for buffalo hunting and not stably occupied in the pre-reservation period is indicated by the Shoshones' ignorance of the hunting grounds in the surrounding mountains. Captain Jones used Shoshone guides from Camp Brown on the new Wind River Reservation when he undertook his exploration of Yellowstone Park in 1873. The captain and his party penetrated the Owl Creek Range, north of the reservation and found at the head of Owl Creek a lovely park (Jones, 1875, p. 54): This park bears many evidences of having been used as a hiding place. Our Indians knew nothing of it, and yet there are all through it numerous trails, old lodge poles, bleached bones of game, and old camps of Cheyennes and Arapahoes.