The first earnest attempt to explore the valley of the upper Yellowstone was made in 1859, by Colonel Raynolds, of the Corps of Engineers. His expedition passed entirely around the Yellowstone basin, but could not penetrate it. Ten years after Colonel Raynoldss unsuccessful attempt to solve the problem of the Yellowstone, a small party under Messrs. Cook and Folsom ascended the river to the lake, and crossed over the divide into the Geyser Basin of the Madison. The general public were indebted for their first knowledge of the marvels of this region to an expedition organized in the summer of...