For example, in Yellowstone the climate warming has kept the snow at a lower level than in the past and has given the elk the ability to populate higher ranges than before.

While overhunting is a significant contributing factor, the elk's near extinction is mainly attributed to human encroachment and destruction of their natural habitats and migratory corridors.

A year later, twenty-one elk from Jackson Hole, Wyoming were reintroduced to South Dakota's Wind Cave National Park for population increase.

Population numbers of elk in Nebraska continued to increase through the 1970s and 1980s, to a level in which complaints from landowners in the Pine Ridge region led to the implementation of relatively liberal hunting seasons in the late 1980s.

Not all of these elk have all the habitat to be successful in large numbers; supplemental feeding programs are used to compensate for lost winter range .

[citation needed] CWD affects the brain tissue of infected elk and is similar in symptoms to bovine spongiform encephalopathy (BSE), commonly known as mad-cow disease (MCD).

Environmental and CWD problems in Estes Park, Colorado, and, on a greater scale, throughout the western North America have governmental policy makers searching for solutions.