Even in the dead of winter on a frozen Milwaukee River, there are signs the river is making a comeback.
Take a walk with the Urban Ecology Center's Ethan Bott and he can show you where beavers have been hard at work.
Trees, some more than a foot across, show marks of where beavers have been biting.
"Usually they're going after smaller trees for food because they're eating the bark and the twigs and branches," Bott said.
The beavers are tucked in for the winter right now, but evidence of their work is everywhere.
The classic v-shaped notches and trees on their side are key signs beavers are flourishing.
Destruction is a good thing because beavers belong here.
"They were nature's engineers, really. They were the ones damming up the rivers, slowing the flow of water," Bott said.
Milwaukee and beavers have a long history.
The first white settlement in today's Milwaukee was a small fur trading post set up in 1795.
According to the Wisconsin Historical Society, beavers caught in Milwaukee were shipped as far as Paris and London where they became fashionable hats.
Good for business, bad for the beavers.
"So they were really decimated throughout North America. Combine that with Milwaukee becoming a city, urbanization, channelizing the rivers, pollution, it really pushed beavers out of Milwaukee for probably close to a century," Bott said.
Thanks to the work of the Urban Ecology Center, Milwaukee Riverkeepers, and others, the river is coming back to life.
That beavers want to be here and eating these trees is a thing to celebrate.