North American beaver ("Castor canadensis") were re-introduced to the Carson River watershed around 1940 and have thrived since. There are eyewitness accounts of beaver in the upper Carson River through 1892. The Washo people who lived in the eastern Sierra with hunting grounds extending as far west as Calaveras County, have a word for beaver, "c'imhélhel". Powers reported that the northern Paiute wrapped their hair in strips of beaver fur, made medicine from parts of beaver and that their creation legend included beaver, which they called "su-i'-tu-ti-kut'-teh". Given the hydrological connection of the Humboldt River and Sink to the Carson Sink during flood years (as recently as 1998), it is not surprising that beavers were historically extant on eastern Sierra watercourses. Peter Skene Ogden, on a Hudson's Bay Company expedition to the terminus of the Humboldt River, wrote in his diary on May 15, 1829, "In no part have I found beaver so abundant. The total number of American trappers in this region at this time exceeds 80. I have only 28 trappers... The trappers now average 125 beaver a man and are greatly pleased with their success." James "Grizzly" Adams trapped beaver in the Carson River around 1860, "In the evening we caught a fine lot of salmon-trout (cutthroat trout), using grasshoppers for bait, and in the night killed half a dozen beavers, which were very tame." Adams' account is consistent with a 1906 newspaper article in the Nevada State Journal that the Mason's Valley of the nearby Walker River in Yerington, Nevada was well known to "the early trappers and fur hunters...Kit Carson knew it to the bone...The beavers of course were all trapped long ago, and you never see an elk nowadays..."