I'm John Bachelworth, Professor Lila Philip of the College of Holy Cross. Her new book is

Beaver Land, how one weird rodent made America. Not only that, but it's teaching America about

the rivers. The rivers that flood, the rivers that retreat in the drought, the rivers that

are surrounded by settlements that are either flooded out or too close when the flood comes.

The professor introduces us to Dr. Denise Burtstead and we go to the Yale Myers Forest and the

professor invariably has an episode where she has to find a walking stick because she winds

up in these wetlands about to tumble into the water. But here we are, we have a walking

stick. What are you learning from Dr. Burtstead, professor?

Well, I think the first thing that I learned from Dr. Burtstead, who is a wonderful researcher

and lecturer, is that a river is not just the Hudson River or the Hussetonic or the Connecticut

River. It's really this intricate system of Brooks and streams and creeks. It's every

little trickle of water that's going through the land that's interconnected. We need to

think of the river system as almost like a fan of arteries and veins that spreads out

through the land. And once you think about the river system that way, no longer just

as one single current, but this multithreaded, braided, maybe messy, interacting network

of veins and lines of water, then I think you can start to understand why beavers are

so important because they will move throughout this system, swelling it into wetlands so

that pretty soon all along that network, you have beaver ponds that are like beads along a chain.

And then the water is allowed to slow down and sink down. And that begins to really solve

our current problems of water moving just too quickly through the watershed so that it

rips through and rips out the top soil. It doesn't get cleansed. And it also means that our land

is dried out. So like last summer here in Connecticut, we had a lot of rain and then we had a drought

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