It might come as a surprise, but an estimated 10,000 to 20,000 Mandan lived in and around the confluence of the Heart River and Missouri River in the 16th century. And the Heart River, particularly the area around the confluence, represented the “hearth” of the world and was important to their creation story.
Elm trees, once abundant and widely distributed in North Dakota and highly valued as an ornamental died by the thousands, mostly in the 1970s. Something similar may occur with ash trees and the emerald ash borer.
A single cottonwood tree can produce a staggering number of small seeds each year. Estimates range from around 25-48 million. But of course, the chances of a seed becoming established and living to maturity are extremely slim.