OK, I'll be the dumb one and ask.
Is the 40Mi herd named for being 40Mi from some town/trailhead or did someone see the herd from the top of some hill way back and decide that the migrating herd was 40Mi long?
Fortymile is a river in NE AK and the Yukon, named during the gold rush.
from Wikipedia:
History[edit]
Prospectors named the river after gold was discovered there in 1886. The name reflected the distance of the river mouth from Fort Reliance, a former Hudson's Bay Company post upstream along the Yukon River.[3] Miners eventually extracted more than a half-million ounces of gold from the Fortymile watershed.[5] After the gold discovery, two Alaska Commercial Company traders, Jack McQuesten and Arthur Harper, built a post at the mouth of the river.
