The mountain goats at Olympic National Park in Washington have worn out their their welcome and park officials are moving ahead with plans to get rid of them.On Monday the National Park Service released a mountain goat management plan, laying out three methods of dealing with the population, which park officials say not only is damaging the environment but is dangerous to people.One method is killing the animals with shotguns or high-powered rifles. The other is relocating them. And the last option is a combination of the two.That is the preferred plan but would likely take years, said Louise Johnson, the park's chief of resources management.First helicopters would capture the goats in drop nets. Next a crew would tranquilize the animals, putting them in slings under the helicopter, which would carry them to a staging area. From there, they would be placed in trucks and driven hours to their natural habitat in the North Cascade Mountains.Some of the goats — roughly half — Johnson estimates, would have to be killed because crews wouldn't be able to access them in remote, rugged terrain.There are an estimated 600 mountain goats in the park today and the population is growing by about 8 percent a year, Johnson said.They were likely introduced to the park the 1920s for hunting purposes."It was just the wrong thing to do," she said; the animals are an exotic species in an area that hadn't evolved to tolerate them.Apart from doing what goats do (eating everything in sight), they've also managed to whittle away at native plants through another action."They're really good at wallowing — laying down in the dirt and taking a dirt bath," Johnson said. That has had the effect of denuding large areas of sensitive native plants.The park has always dealt with the goats on a case by case basis, Johnson said, but it wasn't until 2010 when they got serious about the problem."We had a fatality due to a mountain goat basically goring a hiker," Johnson said.The goats will approach people, Johnson said, because they love salt, which is lacking in the park, and the goats are fond of nibbling on backpacks salty with sweat."They are lethal with those nice horns," Johnson said.The plan is open for public comment for 60 days, until Sept. 26. Park officials hope to reach a final decision by Spring 2018. Copyright 2017 NPR. To see more, visit http://www.npr.org/.