Yellowstone’s isolation was not effectively invaded and broken until the decade of 1860. This narrative will explain how early, trapper observations drifted into oblivion, and later, miner excursions faded into indifference. Hence, the first conclusive visitations were those made by the Folsom-Cook party in 1869 and the Washburn-Langford-Doane Expedition of 1870. Why did Wonderland remain unknown to the world so long? Surely the answer is found in its relative inaccessibility. Yellowstone is a sequestered region, mountain-locked by the Absaroka, Teton, Gallatin, Beartooth, and Snowy ranges. Here, then, is a plateau a mile and a half above sea level, encircled by a still loftier quadrangle of rocky barriers. Some of these culminate in peaks and ridges that rise 4,000 feet above the level of the enclosed table land. Of course there were a few yawning, ever-difficult canyon approaches, cut by foaming mountain torrents and several high, snow-choked passes suitable for late summer use. However, they were far removed from the principal arteries of pioneer travel, and they still remain apart from the main avenues of trade. Even now, these same bulwarks of nature, and their concomitants of snow and wind, exclude traffic from the region for half the year. Consider, then, the situation when all travel was on foot or horseback, and bases of supply were far away from all approaches to this mountain crown. Adequate mountain exploration necessitated large parties and elaborate outfits in the middle nineteenth century. From these circumstances it is easy to understand why Lewis and Clark missed Yellowstone. They adhered quite closely to the Missouri River thoroughfare. However, as an incident of an extensive side trip on their return, Clark and a detail of ten took an alternate route that eventually brought them upon the Yellowstone River near the present site of Livingston, Montana.[16] Previously, while at Fort Mandan, they had learned that the Minnetaree Indian name for the river was “Mitsiadazi,” which means Rock Yellow River. The French equivalent, Roche Juane, was also in common use among the Indians and trappers, although when or by whom the name was given is unknown. American trappers called the river “Yallerstone!” A segment of the stream was trapped in 1805 by Antoine Larocque’s party of North West Company trappers. They struck the river at a point twenty trapping days above its mouth, which was reached on September 30.[17] The fact of the name’s currency is further attested by Patrick Gass’ significant journal entry on July 1, 1806: “Perhaps Capt. Clarke [sic] who goes up the river here, may also take a party and go down the Riviere Juane, or Yellowstone River.”[18] Beyond the Indian stream names, little information concerning the area was ascertained by Lewis and Clark at that time.