To help you learn more about our state animal, Think Out Loud compiled this list after talking to Frances Backhouse, author of "Once They Were Hats: In Search of the Mighty Beaver."
1. Oregon was once home to a tiny prehistoric beaver. It weighed 1 to 2 pounds, and you could have held it in your hands.
2. There was also an enormous prehistoric beaver. It was as much as 8 feet long and may have weighed 440 pounds.
3. At the height of their population, there were 400 million beavers in North America. Trapping brought that number down to around 100,000. But beavers are coming back: a recent estimate puts the population at between 10 and 50 million.
4. In the Middle Ages, the Catholic Church decreed that beavers tails were fish, meaning they could be eaten during Lent. (The rest of their bodies were considered meat and were off-limits between Ash Wednesday and Easter.)
5. Beavers have two glands in their nether regions that make something known as "castorerum." It has been used as a leathery note in perfume and in a flavored Swedish schnapps. Backhouse describes the smell as "sweet and musky and acrid all at once, like flowers blooming between creosote-soaked railroad ties in the heat of summer."
6. These days, the castor glands are the most valuable beaver body part, even more than the pelt.
7. One reason beaver fur is so sought-after? They have very dense pelts, with anywhere from 12,000 to 23,000 hairs in each square centimeter.
8. There is still a market for beaver fur. In 2010, at the North American Fur Auction, 157,207 pelts sold in two hours and 17 minutes. Many of them went to China.
9. Steel traps didn't really catch on for hunting beavers until 1850, when a lightweight, reliable trap designed by a young member of the Oneida Community — better known at the time for their silverware — began to be machine manufactured.
10. It can be tough for archaeologists to distinguish between things that were built by beavers and things that were built by early humans — they did, after all, work with the same materials: wood, earth, and stone.
Eager to learn more about the beaver? Backhouse will read from her book at Powell's City of Books at 7:30 p.m. Friday.