We have noted the visit of McKenzie’s brigade of British-Canadians to the Upper Snake and a region of boiling fountains, in 1818-1819, as reported by Ross. Now, in 1824, Ross himself conducted the second British invasion of Yellowstone Park, while crossing from Okanagon to the headwaters of the Missouri. In the foolscap folios which make up his official report, the entry for April 24 reads: “We crossed beyond the Boiling Fountains. The snow is knee-deep half the people are snow-blind from sun glare.” So British traders have supplied the first clear record of Yellowstone thermal wonders to follow the hazy notations along Colter’s route on The Clark Map of 1810. [Illustration: TRADE BEADS AND HAWK BELLS] VI. “Jackson’s Hole”: Era of the Rocky Mountain Fur Company, 1825-1832 Late in 1824 General Ashley, journeying west to reap the winter’s harvest of furs, approached the mountains by way of the little-known South Platte route and the Colorado Rockies and explored the lower Green River. In the summer of 1825 on Henry’s Fork of the Green (near the Wyoming-Utah line) he inaugurated the annual rendezvous of the mountain trappers, which provided a more flexible system of fur trading than the “fixed fort system” which had hitherto prevailed in the Western fur trade. The beaver catch brought in this first year was of such magnitude that Ashley was assured of a substantial profit. With Smith and a strong guard he took his prize by pack train to the Bighorn, by bullboats to the mouth of the Yellowstone, and by keelboats down the Missouri River to St. Louis. Jedediah Smith left Flathead House in 1825 with Peter Skene Ogden of the Hudson’s Bay Company, but left him in time to rejoin his comrades at the rendezvous. When the reunited Americans exchanged tales of their adventures, it is possible that Smith offered a glowing account of the Jackson’s Hole region. Whatever the inspiration, Bridger and Fitzpatrick are reported to have headed there to resume trapping operations, after seeing Smith and Ashley safely down the Bighorn. This may have been the first large-scale trapping venture in which Jackson’s Hole was a primary objective. The rendezvous of 1826 took place near Great Salt Lake. The turnover of furs was immense and, having made his fortune, General Ashley sold his interests to three of his most able employees, Jedediah Smith, David E. Jackson, and William Sublette. Smith left the rendezvous to lead a band southwest across the desert to the Spanish settlements of California, being the first to make this perilous passage. Jackson and Sublette headed for the Snake River country to trade with the Flatheads, taking a large force of trappers.