As part of a highly controversial program, the sharpshooters were called to remove the park's invasive population.
There are more than 400 national parks, according to the National Park Service, which are available to everyone, every day.
Invasive species are now a "huge" issue in national parks and the problem is "far, far worse now" than it was twenty years ago, researchers say.
Mary Joanna Gomez, 56, was recovered "alive and in a stable condition" after a National Guard C-130 aircraft spotted the help message after days of intense searching, the National Park Service said.
"I would compare it to building a wall over your parents' graveyards. It would have the same effect," said Tohono O'odham Nation Chairman Ned Norris Jr.
The National Park Service confirmed the victims's family returned to the park and collected his remains. The victim, who was last week four years ago, was named as Feiyang "Isaac" Xiang, 21.
The encounter is just the latest example of Yellowstone visitors placing themselves and others in danger by getting too close to bison in the park.
Bison have injured more people in Yellowstone than any other animal, according to the National Park Service.
Fireworks displays were previously stopped due to fears that a pine beetle infestation in the area would cause a fire.
The giant water bug is believed to be the most painful of all insects.
First Bears Ears, now the Grand Canyon.
The National Park Service says the organizers of an annual art event can't display a statue of a naked woman because it's too tall and would ruin the grass.
Almost 1.32 million disposable bottles were not purchased on an annual basis, thanks to the Obama-era policy.
The president is trying to bully this country into submission—but we don't have to let him.
"Let it burn" approach to forest fires bumps against locals' fears and the need to capitalize on tourist season.
Nearly a century after Woodrow Wilson established the NPS, it looks ahead to the next century.