The animal that once could have made a strong case for being Missouri’s most important mammal is now one of the state’s seldom-mentioned creatures.

Today, in terms of human consideration, Missouri’s beavers live their lives in relative obscurity. They’re still considered a game animal; beavers are a furbearer and are part of Missouri’s trapping season. Missouri’s trapping season for beaver runs from Nov. 15 through March 31. (See “Wildlife Code of Missouri” for details.) However, beavers’ primarily nocturnal routines keep them out of most people’s views and concerns. The only time beavers are usually noticed is when the two most obvious signs of their existence – dams and tree-chewing – cause problems for humans.

However, a look at the history books will show beavers didn’t always have such a low profile. Deer may be the primo mammal for today’s Missourians, but their significance in the state today isn’t anywhere near the stature once held by beavers. It could be argued very easily that beavers literally put Missouri on the map as a state. At this time of year, as some Ozarkers switch their outdoors interests from hunting to trapping, it’s a good time to take a closer look at the animal which was once Missouri’s most prestigious furbearer.

In the 1700s, it was an interest in beaver pelts that lured the first explorers and settlers to the land that would become Missouri. In 1763, a desire to control the beaver pelt trade led Pierre Laclede and Auguste Choteau to found the trading post of St. Louis at the strategically located convergence of the Missouri and Mississippi rivers. In less than 100 years, the beaver pelt trade had transformed the small fort of St. Louis into the fur-trading capital of the world. In the early years of statehood, the trade in beaver pelts pumped millions of dollars into Missouri, thus ensuring that the state’s fledgling economy got off to a strong start.

Though the beaver’s hey-day in Missouri is history, the animal is still an interesting member of the state’s wildlife world. Their wood-chewing habits are the beaver traits that are familiar to many people. In winter, woody vegetation comprises nearly 100 percent of a beaver’s food intake. (At other times of year, plants, leaves and grains comprise part of their food intake.).

Their wood ingestion is linked to another well-known beaver characteristic – the construction of large lodges used for brood-rearing. Many people refer to these lodges as “dams” because of their penchant for restricting water flow. Missouri beavers don’t build lodges as often as beavers residing elsewhere on the continent. Most beavers in Missouri build their homes in stream banks, presumably because they instinctually know the fluctuating water levels of many area waterways make lodges impractical.

The typical Missouri beaver bank den consists of a chamber between two feet and three feet across and one to two feet high and situated above normal water level. It is reached through a tunnel 12 inches to 18 inches in diameter and 12 to 50 feet in length. The tunnel’s entrance is usually below water level.

Where beavers build lodges, those structures may be up to seven feet high and 40 feet in diameter. There is a single chamber inside that’s four feet to five feet wide and approximately three feet high. There may be one or two passages to the outside; the entrances to both of which are under water.

Beavers are occasionally problematic. However, for most of us, beavers are either a valuable fur-bearer or merely an interesting mammal that we seldom see. More information about beavers, other fur-bearing mammals and Missouri’s trapping season can be found at your nearest Missouri Department of Conservation office or at