Wrangellia - an exotic terrane formed about 225 Ma. It later drifted in from the Pacific Ocean and attached itself to North America by about 120 Ma.
And we begin going downstream on about 5,000 cfs. We would end the trip on the Alsek River at about 130,000 cfs.
Bear claw marks on an Aspen tree.
Dryas, a widespread Arctic plant. There is a glacial stadial (shorter time period) called the Younger Dryas, when planet Earth went from relatively warm glacial conditions back to glacial conditions between about 12,900 and 11,500 years ago. It is believed that the onset of the Younger Dryas occurred over a short 10-12 year period and that it ended over an equally short 40-50 year period.
Amazing dikes running through the thin bedded limestone.
Ptygmatic folds in the schist rocks.
Lush vegetation of the temperate rain forest.