These friendly Indians encamped with us that night, and on the following morning the old chief informed us that some of his party had a few "mulas para _swap_" (mules to trade; for having learned the word _swap_ of some American traders, he very ingeniously tacked it at the tail of his little stock of Spanish). A barter of five mules was immediately concluded {23} upon, much to our advantage, as our teams were rather in a weak condition. Old Tab and his party then left us to join his band, which, he said, was located on the Faux Ouachittâ river, and we never saw aught of them more.[80] After leaving the Fort we generally kept on the ridge between the Canadian and the North Fork, crossing sometimes the tributary brooks of the one and sometimes those of the others. Having travelled in this manner for about eighty miles, we entered one of the most charming prairie vales that I have ever beheld, and which in the plenitude of our enthusiasm, we named 'Spring Valley,' on account of the numerous spring-fed rills and gurgling rivulets that greeted the sight in every direction;[81] in whose limpid pools swarms of trout and perch were carelessly playing. Much of the country, indeed, over which we had passed was somewhat of a similar character--yet nowhere quite so beautiful. I must premise, however, that westward of this, it [Pg112] is only the valleys immediately bordering the streams that are at all fit for cultivation: the high plains are too dry and sandy. But here the soil was dark and mellow, and the rich vegetation with which it was clothed plainly indicated its fertility. 'Spring Valley' gently inclines towards the North Fork, which was at the distance of about five miles from our present route. It was somewhere along the border of this enchanting vale that a little picket fort was erected in {24} 1822, by an unfortunate trader named McKnight, who was afterwards betrayed and murdered by the faithless Comanches.[82] The landscape is beautifully variegated with stripes and fringes of timber: while the little herds of buffalo that were scattered about in fantastic groups imparted a degree of life and picturesqueness to the scene, which it was truly delightful to contemplate.