It is easy to conclude from the selected excerpts from the expedition's journals that the Corps of Discovery found the Plains teeming with bison. Daniel Botkin, however, puts the Corps' experience in a broader perspective.
"There were only 60 days during the outward journey that the expedition reported any live buffalo. These reports occurred mainly in sets of consecutive days that fall into 17 separate episodes from June 6, 1804, to July 15, 1805, a period of 404 days. They saw buffalo on only 15 percent of the days they were in buffalo country."1
David Dary has tabulated the bison population in North America beginning in 1888, as estimated by various contemporary authorities. It is thought that in that first year there were 1,300; by 1895 it was down to 800. By 1900 the number had risen to 1,024, and it increased thereafter by increments of a few hundred annually until the 1970s, when the totals grew by several thousand each year, until there were an estimated 98,000 head by 1989.2 Today, there are 200,000 head on this continent.
Clearly, the recovery of the American bison is one of the most remarkable and satisfying stories of environmental recovery in the 20th century.