By the end of that century, the Kiowas had drifted south into the region embraced by the present State of Colorado, probably being forced to do so by the pressure of the Sioux, Cheyennes, and Arapahoes, who were at that time advancing from the north and east. As the Kiowas advanced southward, they encountered the Comanches; this resulted in warfare that lasted many years, in the course of which the Comanches were gradually driven south of the Arkansas River. When, finally, the war was terminated, an alliance was effected between the two tribes, which thereafter remained unbroken. In 1806, the Kiowas were occupying the country along the eastern base of the mountains of the Pike's Peak region. From Lieut. Zebulon Pike's narrative, we learn that James Pursley, who, according to Lieutenant Pike, was the first American to penetrate the immense wilds of Louisiana, spent a trading season with the Kiowas and Comanches in 1802 and 1803. He remained with them until the next spring, when the Sioux drove them from the plains into the mountains at the head of the Platte and Arkansas rivers. In all probability their retreat into the mountains was through Ute Pass, as that was the most accessible route. In the same statement Lieutenant Pike mentions Pursley's claim to having found gold on the headwaters of the Platte River. By the year 1815, most of the Kiowas had been pushed south of the Arkansas River by the Cheyennes and Arapahoes, but not until 1840 did they finally give up fighting for the possession of this region. The Cheyennes and Arapahoes were of the Algonquin linguistic family, whose original home was in the New England States and southern Canada. When first heard of, about 1750, the Cheyennes were located in northern Minnesota. Later, about 1790, they were living on the Missouri, near the mouth of the Cheyenne River. Subsequently they moved west into the Black Hills, being forced to do so by the enmity of the Sioux. Here they were joined by the Arapahoes, a tribe of the same Algonquin stock, and from that time on the two tribes were bound together in the closest relations.