“Our road started uphill and rose higher and higher, but very gently. Wyoming makes less fuss about its elevation than any place I know. To our left was the wide sandy pass used by migrants of the sixties. A later generation of indigenous Casperites have named it Emigrant Gap, one of a long series of Emigrant Gaps that puncture the trail clear to the Pcific coast. The highway uses a parallel pass nearby. Just beyond it we found Poison Spider Creek, all the wrong colors for respectable water and very scummy, but wholesome in comparison with the neighboring supply, for the emigrants now had a new trail bugbear—alkali.
The travelers had seen alkali water along the Platte, but with the river running near by, the discolored pools were little temptation to the cattle. Now the migration wallowed in billowing dust (also tinctured with alkali) that choked and almost blinded the animals. Their ears, ey rims, and nostrils were coated an eighth of an inch thick, and the implacable brassy sun baked it solid. Anyting that looked like water caused a rush in its direction. . . .
And here again, it was all a matter of preparedness. After the enormous migrations of ’49 and ’50 had learned what not to do, later comers handled the fifty-odd miles of semidesert much better. After all the was good water at short enough intervals to preserve the stock if they could be kept from the poison pools between.”