That included the Milwaukee River, where it's likely no sturgeon spawning has taken place since 1843, when a dam was built across the river near North Avenue. Fortunately, the species fared much ...

But the longevity of the sturgeon in the Kootenai River is waning: It hasn't reproduced in real numbers in at least 30 years due to habitat change caused by Libby Dam, which shut its gates in 1975.