Bullish on Beavers

While some cattle ranchers scorn the giant rodents, others are putting beavers to work

• Stephen Stuebner
• Apr 01, 1994

Lew Pence, a lean and leggy fellow who works for the U.S. Soil Conservation Service, strides along Corral Creek, an aspen-lined mountain stream in south-central Idaho. Pence observes the diverse plant life thriving in the meadow about 30 feet from the creek's edge. "Yep, them beavers been busy in here," Pence says, grinning. "Just look how far the water table has risen in here already."

Pence wears a white baseball cap with an orange "Beavers" insignia on the front. For Pence, the Oregon State University sports logo is a booster sign for real beavers, Castor canadensis. He crouches and inspects new willow shoots, grasses and sedges sprouting in the shadow of cottonwood and aspen trees. Overhead, a red tailed hawk screeches and takes off from its nest atop a tall black cottonwood. Mallards flush from the creek and quack as they pull into flight, zooming by the thick vegetation. Red-winged blackbirds issue terse calls in the alder bushes. Giant mosquitoes scout for fresh blood in the moist area.

The area is so moist that rancher Jon Mellen, owner of this land, has stopped worrying about running out of water. Perhaps that's not surprising this year, given last year's drenching rains and deep snow pack. But two years back, during the height of the worst drought in southern Idaho's history, the Corral Creek meadow was like an oasis in the desert. The reason? For about five years, a native colony of beavers has been busy expanding a network of dams on the creek, from high in the mountains to the valley bottom on Mellen's 10,000-acre Hot Springs Ranch.

The dams help raise the water table and create lush meadows (thereby expanding the area in which nutrient-rich plants and grasses grow). The dams also trap eroding soil, improve water quality and ultimately create more habitat for wildlife. But there's also a bottom line here: The lush meadows bordering beaver ponds provide a vibrant crop of grass for livestock. With prudent and vigilant management of livestock and beavers, Mellen can put more pounds on his cows than he could before.

Mellen is one of about a dozen ranchers in a four-county area of south-central Idaho who are bullish on beavers. While some folks scorn the big rodents for their propensity to choke culverts and clog irrigation ditches, ranchers are discovering that beavers can be a valuable tool for restoring riparian areas, the green strips of vegetation that border waterways and provide most of the habitat for wildlife along Rocky Mountain streams and elsewhere in the West.

Mellen and his neighbors are not alone. Ranchers in Colorado, Oregon, Montana, Wyoming and Nevada are also working with federal officials to rejuvenate riparian areas with beavers. "Beavers are now looked upon as an integral part of stream recovery," says Wayne Elmore, a national riparian restoration expert for the Bureau of Land Management (BLM) in Prineville, Oregon.

In many cases, Elmore and Pence believe that beavers are key to reversing the ecological damage caused by livestock-damage that has been compounding since European settlers drove cattle by the tens of thousands into the West in the 1800s. In those days, ranchers viewed beaver dams, willows and thick brush as impediments to livestock grazing and watering. Trappers removed the beavers; ranchers and hired hands shot them. Meanwhile, cattle quickly learned to cope with sizzling hot summer days by wallowing in stream bottoms. Throughout the West, livestock have eroded and compacted stream banks, fouled the water, stripped riparian vegetation and decreased streams' abilities to store water. With the beavers gone, overgrazing, combined with raging spring snow melts, turned many streams into deep, barren gullies. BLM studies indicate that more than 60 percent of the riparian habitat on western public lands is in "poor" condition. Some ranchers have tried to rebuild streams with expensive rock dams, only to see their handiwork washed away in a spring flood. Beavers, in contrast, do the engineering work for free, and if a dam fails, they rebuild it.

Slowly, public-land officials, along with some ranchers, are working on ways to reverse a large part of the damage. In 1990, the BLM and Forest Service developed tougher regulations for riparian areas on public lands. And last year, Interior Secretary Bruce Babbitt announced a plan for range reform on most public lands that includes higher grazing fees and penalties for land abuse.

In practice, to restore riparian areas, federal range managers must gain the cooperation of ranchers who hold grazing permits-and that's not always easy. Ranchers often harbor a distrust of the government; some consider public grazing allotments to be their own land. And ranchers often detest beavers. "I don't know why some people have such contempt for beavers," Pence laments. "It's hard to get people to let loose of that. Heck, there's even some people in my agency that think I'm crazy."

Probably no one can convince a cowboy of anything as well as another cowboy. Retired Colorado rancher Bill Barnard has won numerous awards for turning the Cathedral Bluffs BLM grazing allotment near Meeker, Colorado, into a shining example of range stewardship. He gives beavers a heap of credit for his success. He says of fellow ranchers, "Maybe they don't like beavers, maybe they don't want beavers, but I tell them maybe they'd better try beavers or they'll be out of business."

When Barnard moved 1,000 head of cattle into the area in the late 1970s, he had trouble finding enough grass to feed his herd. Cattle had hammered the 100,000-acre allotment. Douglas Creek, which ran through the scrubby pilion-juniper country, had been widened and flattened by livestock clear to the headwaters at 7,200 feet. "It was just pitiful looking," recalls Bob Fowler, a BLM range conservationist.

Fowler and Barnard crafted a new grazing management plan for the allotment. The first step: Halt livestock grazing in the headwaters for several years. A remnant population of beavers quickly moved in and started building dams. The resulting ponds raised the water table and spawned tremendous willow and grass growth. Barnard then let cattle graze those areas only in spring and fall.

To keep livestock from wallowing in the creek, he herded the animals and moved them to alternative sources of water at other times of the year. Though some ranchers say they can't afford to herd their livestock, Barnard says it's imperative for good stewardship. "I've been a cow man all my life, and it's my feeling that you better get around and take care of your cows," he says. "If we don't start taking care of our public lands, we'll get kicked off."

Now, 16 years later, adjacent to hundreds of beaver dams, tall coyote willows have grown back, and songbird populations have skyrocketed. A recent U.S. Fish and Wildlife Service study on Douglas Creek counted 93 bird species. In contrast, non-beaver-ponded stretches farther down the creek had lower bird counts and less species diversity. "Before the beavers moved in, I never saw a duck in there," Barnard says. "Now there are thousands of them, including several kinds I've never seen before."

Barnard and others caution, however, that beaver numbers must be kept under control to obtain the optimum benefits. For one thing, beavers are prolific consumers of woody vegetation; their teeth grow continuously, and they instinctively chew to keep their teeth in check.

In Idaho, Pence recommends thinning out beaver populations on a regular basis if necessary. In areas where trees and woody material are in short supply, one solution is to move excess animals to new territories. Pence and some southern Idaho ranchers have live-trapped and moved about 145 beavers into about 25 different creeks since 1986. Still in the early stages, the beaver-promotion efforts appear to be working as long as beaver populations are kept under control. "I think beavers, in conjunction with proper grazing management, are the most economical way to bring these badly eroded riparian areas back to health," Pence says. Beavers are even making a comeback in their native range near mountain streams where trappers once caught them by the tens of thousands.

The largest rodents in North America, beavers build dams in streams to create deep ponds for housing a winter lodge. In nearly every beaver pond, the tell-tale sign of a beaver lodge rises like a cone above the water's surface. Beavers cache woody materials inside the pond and the lodge for winter food, and they raise a litter of two or three kits each year. Left alone, beavers proliferate rapidly, expanding their territory as long as the food supply allows.

Beavers are known as a "keystone" species, meaning their dam-building wetland-creating activities support many other species. Beaver-created wetlands provide multiple benefits for wildlife, particularly songbirds, waterfowl, aquatic insects, rodents and fish. A study in the Blue Mountains of eastern Oregon found that as many as 350 different species of wildlife depend on healthy riparian areas for food and shelter. Another study showed that about 75 percent of all wildlife species on western public lands depends on healthy riparian areas for food, shelter or both.

Beaver ponds in western streams increase wildlife diversity and species richness. One 1990 study by the U.S. Forest Service's Intermountain Research Station on Summit Creek in central Idaho found that beaver ponds supported three times more songbirds than an adjacent riparian area with no beaver ponds.

On a spring day, Pence drives toward Galena Summit, north of Sun Valley, to visit a series of beaver ponds in the headwaters of the Big Wood River. A pair of mallards swims in one of the larger ponds. Killdeers issue their ear-splitting shrieks as he walks near their nest. Thick pockets of willows surround the ponds next to the steep-rising Boulder Mountains in the Sawtooth National Forest.

This wet meadow was a trampled dust bowl when Pence was a kid. "Now, it's damn-near moose habitat," he says with a chuckle. Butterflies flutter atop the willows. Snipes wade into a pond and dip their bills into the water. Small fish zing out of sight under the bank for cover. "The beavers have created one hell of a wetland here," says Pence, the beaver booster with the Beaver hat.

Boise free-lance writer Stephen Steubner visited several beaver streams in researching this article.