By Christine MacDonald
Race cars aren't the only things that have returned to Belle Isle.
Beavers are back after an absence of about 100 years, and experts say they're another sign the Detroit River is coming back.
Park officials discovered the animals' dens and tell-tale tooth-marked tree stumps in February in the island's forest-covered canals. But it wasn't until last week, when a park visitor snapped a cell phone photo of a beaver swimming in the Blue Heron Lagoon, that staffers were convinced.