In the northwestern part of the strip are extensive salt marshes, and to the east of them is the great salt plain, on the Salt Fork of the Arkansas River, comprising thousands of acres. In some tracts the salt is formed on the surface of the ground and along the edges of the streams. There are also vast fields of salt beautifully crystallized, which greet the eye of the traveler a long distance before he reaches them. It would appear that there is salt enough to supply the whole country, and it can be had merely for the cost of handling. Hitherto it has been extensively used on the neighboring cattle ranches and has been hauled to towns in southern Kansas and sold. All the Indians of the territory have had free access to it for their supplies. In wet weather and high water there is little or no salt to be seen, but after three or four dry days it appears again on the surface, as before described, from six to twelve inches thick. On September 27, 1719, Lieutenant du Tisne, from the French garrison at Kaskaskia, raised the French flag on these salt plains and took possession in the name of his king. He was the first white settler to enter the strip from the east, as Dennison had been from the west.