The mud-caked bull elk thrashes the brush with his antlers, then sprays his belly with urine. His sides heave with heavy breath. The animal’s massive neck, swelled far beyond normal size, tilts back. Finally, the sound comes—at first deep and chesty, then rising to high, buglelike notes that shatter the Arkansas autumn silence.

Arkansas? Yes. And Kentucky, Pennsylvania, Michigan, Wisconsin and other surprising places, too, as a species once almost extinct expands its domain. "Elk have become a really big deal," says Glen Matthews, a biologist with the Michigan Department of Natural Resources. "Returning them to the East is an idea whose time has come."

In the West, however, a new disease lurks in the shadows, raising a threat to continued elk prosperity. And in Yellowstone National Park, elk have sparked a controversy by potentially overgrazing some of the country’s most important wildlife habitat. For rather reclusive animals, elk certainly manage to keep scientists, conservationists and wildlife managers hopping.

North American elk are generally considered to be the same species as the red deer of Asia and Europe. Among their American relatives, elk are second in size only to moose: An adult bull may stand 5 feet tall at the shoulder, weigh as much as 1,000 pounds and support massive antlers. Females, called cows, are shorter and perhaps 200 pounds lighter. Mostly tan or brown, elk sport a distinctively white rump—for which the Shawnee named them wapiti.

Elk can live in many habitats, from rugged mountains to desert valleys to hardwood forests. Though primarily grazers of grass, they also eat other plants—including parts of trees, especially in winter. Wapiti are gregarious, often forming sizable herds. In the fall, bulls compete for breeding rights, with each would-be patriarch attempting to establish his own harem. The rut is marked by occasional antler-clashing duels and the bulls’ frequent bugles, a blend of whistles and screams.

An estimated 10 million elk once occupied part of every continental state except Florida and Alaska, but European settlers and market shooters decimated the herds. By the late 1800s, only about 50,000 elk remained, mostly in the Yellowstone area, and wapiti appeared headed for extinction.

Early in the last century, however, federal and state protections, habitat improvements and relocations set the stage for a comeback, and today America is home to about 1 million elk. Most of these belong to the Rocky Mountain subspecies, but there also are populations of tule elk in California, Manitoba elk in Canada and Roosevelt elk—the largest of all—in Pacific Coast forests from California to British Columbia.

Most elk live in the 11 westernmost contiguous states, but relocation projects have placed wapiti in 12 other states. While some relocations date from the early 1900s, many are recent. Kentucky’s ambitious project—1,800 elk to be released over nine years and an eventual population of perhaps 10,000—began in 1997. Wisconsin got its elk in 1995 and elk were relocated to Arkansas in the 1980s. States such as New York, Missouri, Tennessee and Virginia may soon start elk herds.

Why the surge in elk interest? One of the main movers is the Montana-based Rocky Mountain Elk Foundation, a private conservation group that provides expertise and money—$1.5 million to date—for relocation projects. In addition, the public welcomes new wildlife-watching opportunities. "Elk are huge, attractive, eye-popping animals, and people love having them around," says Michael Cartwright of the Arkansas Game and Fish Commission.

In most eastern elk states, the autumn rut has become a significant tourist attraction. The town of Atlanta, Michigan, prides itself on being the elk capital of the state and holds an annual elk festival. In Pennsylvania, elk are responsible for the opening of new stores, campgrounds, lodging facilities, art shops and trail-ride concessions—to the tune of $1.7 million annually, according to Pennsylvania State University. "Elk are a very big deal here," says Rawley Cogan, a biologist with the Pennsylvania Game Commission.

But having elk around presents problems, too. Michigan wapiti occasionally stop traffic by grazing on the median of busy Interstate 75, and elk once ate all the plastic flowers off graves in a Kentucky cemetery. Other bluegrass wapiti strayed onto a golf course, where a bull repeatedly pulled flagsticks from their holes while his companions stomped around the greens. "Elk track depressions can make putting a real challenge," says Jon Gassett, a wildlife biologist with the Kentucky Department of Fish and Wildlife.

The most serious conflicts arise when wapiti get hungry, which is quite often. An adult elk needs 15 to 20 pounds of food per day—and isn’t shy about getting it from orchards, vineyards, haystacks and crops. Occasionally, farmers take matters into their own hands. In 1999, a Pennsylvania vegetable farmer refused free fencing, then shot 10 elk (nearly 2 percent of the state’s entire population) because they damaged his crops. And it was all legal, thanks to a state law allowing farmers to kill crop-destroying wildlife.

Such actions are rare, however, as farmers and wildlife agencies generally work together to curb elk damage. Michigan wildlife workers sometimes haze elk away from crops, and Kentucky authorities occasionally capture and remove errant elk from farms. Some states also issue special hunting permits to eliminate problem animals and control populations at the same time. Pennsylvania’s main solutions involve fencing (at public expense), enhancing natural habitat to lure elk away and education. "A big part of our program is to convince people that elk are part of our wildlife heritage and that we should share the landscape with them," says Cogan.

While prospects for elk in the East remain bright, a dark cloud looms on the wapiti horizon. In the late 1960s, employees at a wildlife research station in Colorado noticed that some captive mule deer were emaciated, drinking and urinating frequently, drooling, stumbling and standing listlessly with ears drooping. Before long, the animals died. Researchers later named the malady that killed them chronic wasting disease (CWD), a contagion with no treatment and no survivors. In 1981, CWD was found in wild elk, and in 1985, in deer.

CWD may have started as a mutation from sheep scrapie (a similar affliction) and spread to captive animals at the Colorado facility. Or, it might have existed for decades in the wild and was only discovered at the research station. Regardless, the disease frightens conservationists. "CWD represents one of the greatest threats to our wildlife in this century," says Craig Sharpe, head of the Montana Wildlife Federation, a National Wildlife Federation affiliate.

So far, incidence among free-ranging animals remains limited. "As far as we know, CWD exists in the wild only in southeast Wyoming and northeast Colorado," says Beth Williams, professor of veterinary science at the University of Wyoming and a leading CWD researcher. Authorities estimate that only 1 percent of wild elk (and 6 percent of deer) in this 25,000-square-mile area have CWD.

So what’s the problem? Captive elk. After remaining only in Wyoming and Colorado for years, CWD was recently found in some of the thousands of game farm elk that are often shipped around the country. In short order, CWD has appeared among captive elk in Montana, South Dakota, Oklahoma, Nebraska and Saskatchewan.

"It’s only a matter of time before CWD jumps from a game farm and spreads through wild elk and deer herds," says Sharpe. And after years of study, researchers still don’t know how CWD spreads. Its existence at game farms suggests animal-to-animal contact, but the specific vehicle could be saliva, urine, feces, contaminated soil or something else. Simple nose-to-nose contact through a fence might be all that’s needed to turn CWD loose in the wild.

"However it travels, CWD is an extremely persistent agent," says Williams. In an attempt to rid the Colorado research station of CWD, authorities killed the facility’s elk and deer, plowed up the ground and sprayed the area with a powerful disinfectant. When wild elk calves returned to these pens a year later, some of them contracted CWD and died.

In Yellowstone National Park, America’s most famous elk herd has shown no sign of infection. In fact, elk there are so healthy that they may be making the habitat sick. "Yellowstone is grossly overgrazed by elk," says Richard Keigley, an ecologist with the U.S. Geological Survey, "and the negative impact on a variety of wildlife species is extraordinary."

In summer, about 35,000 elk graze throughout the park. Between 15,000 and 22,000 of them typically winter on Yellowstone’s 600-square-mile northern range. Some scientists believe these animals (plus far fewer bison and moose) are eating the habitat into oblivion.

"The northern range is in deplorable condition," says Keigley. "Juniper, spruce, birch, aspen, willows, cottonwoods and virtually every other species of woody plant are all in major decline." He and others have collected a scrapbook of before-and-after photos that show thick vegetation decades ago and stubble today.

But plants aren’t the only victims. When brushy understory disappears, so does habitat for mice, deer and a host of species in between. Fewer aspen, cottonwoods and willows means less habitat for songbirds, the raptors that prey on them, and beavers, which have all but disappeared from the park. Lack of tree roots and beaver dams allow rivers to erode their banks and topsoil to blow away.

Critics say the problem began when Native American hunters and wolves stopped killing Yellowstone elk, and when development outside the park essentially trapped elk on the northern range. As Yellowstone’s elk numbers increased, the National Park Service (NPS) periodically reduced the population by shooting animals or shipping them elsewhere. But increasing public opposition led to the end of this practice after 1968, when officials cut the northern herd to 4,500 elk. Since then, the NPS has relied on "natural regulation," the concept that elk will limit their own numbers by reducing fertility and survival when the population gets too high. "Natural regulation is a scientific fraud, and it may take 10,000 years to repair some of the damage," says Utah State University wildlife ecologist Charles Kay.

The NPS, however, says the northern range should look somewhat battered, because it’s feeding thousands of large animals. "If we killed every elk that ate a lower branch off a tree, we’d have no elk and a lot of bushy trees," says John Varley, director of the Yellowstone Center for Resources. "We have more faith in the processes nature employs than in our arbitrary judgments about how things should be."

According to the NPS, vegetative changes in Yellowstone have been caused by a mix of factors that include elk, other herbivores, fire, drought and a warming climate. A recent study by researchers at Oregon State University indicates that the elimination of wolves from the park may have played a key role. According to the scientists, aspen began to disappear from Yellowstone in the 1920s, the same time that the last wolf was removed from the park. The researchers theorize that wolves benefitted aspen by keeping browsing elk away from groves (where the elk are more vulnerable to attack) and by limiting the creature’s numbers. No one knows exactly what effect the wolf’s recent return to the park may have on this situation, but Yellowstone’s wapiti are likely to remain in the wildlife spotlight for some time.

So it is with the elk among us—quarrels in one quarter, a love affair in others and worry elsewhere. But make no mistake: Elk are here to stay, in more places than anyone a century ago might have imagined. Little by little, these magnificent animals are returning to former haunts. The next time that big bull bugles, the next time antlers clash in a meadow, the next time wapiti hooves pound the sod, it may all be (figuratively, at least) in your backyard.

Gary Turbak wrote about grizzlies in the October/November issue. He sees elk regularly near his home in Missoula, Montana.