Growing up in rural Iowa, roadkill was basically a fact of life. Skunks were the most dreaded, for obvious reasons, but cars mowed down raccoons, squirrels, pets, and — sometimes fatally for drivers and passengers — deer. Roads often pass through ecosystems where a lot of animals make their homes. Which is why, when Montana's department of transportation wanted to build a new road, they built a land bridge for wildlife.

It's not just the little animals, either. Four grizzly bears were among the thousands of animals that died between 1998 and 2010 on the Flathead reservation. So to assuage the tribes' concerns, 41 underpasses and overpasses for fish and wildlife were built. This model may lead to a more wildlife-friendly future for roads, since other highway departments are apparently studying the Montana example.