Last year, under the Obama administration, the U.S. Fish and Wildlife Service also proposed removing the bear from the endangered species list - using the roughly the same language Zinke adopted for his statement, in fact: "The restoration of the grizzly bear in Montana, Wyoming and Idaho during the last three decades stands as one of America's great conservation successes".
The move, which was first proposed by the previous administration of President Barack Obama past year, will go into effect 30 days after it is published in the federal register. The ruling does not affect threatened grizzlies living in other areas of northwestern Montana and northern Idaho.
The bears roam both inside and outside the park, and their range has been expanding as their numbers have grown.
Yelowstone's grizzlies were briefly removed from protected status in 2007 but were re-listed after environmentalists sued, asserting the government had failed to account for such factors as climate change.
U.S. Sen. Steve Daines (R-MT) quickly praised the announcement that federal protections for Yellowstone grizzly bears would be lifted.
"We have more data now, and grizzly bears today still meet the recovery criteria, we have adequate regulatory mechanisms in place, and we have been working closely with the states that if they do choose to allow hunting of the bears, those safeguards will be in effect and we have a really good monitoring plan in place", Cooley said.
With this act, management control of the Grizzly Bear in the Yellowstone Ecosystem returns to Montana, where it belongs.
Interior Secretary Ryan Zinke said Thursday that the recovery of Yellowstone's grizzlies is one of the nation's great conservation success stories.
About 125 tribes have signed a treaty opposing trophy hunting grizzly bears, which Native Americans consider a sacred animal. "Stable population numbers for grizzly bears for more than a decade also indicate that the GYE is at or near its carrying capacity for the bears".
"This has been a priority of the association for years and is a critical first step for the State of Montana to regain management of the bear population" the Montana Stockgrowers Association said. Climate change and invasive species have reduced whitebark pine and cutthroat trout populations around Yellowstone, putting several food sources at risk.
"Grizzly bears have met or exceeded recovery objectives since 2003 and have long warranted delisting", said Mr. Mead in a statement.
That adaptation has meant switching from nuts to a meat-based diet.
"The Trump Administration's delisting maneuver is a gift to trophy hunting and oil and gas interests", Wayne Pacelle, president and chief executive officer of the Humane Society of the United States, tells Newsweek in an email.
"It will be great to see the grizzly bear recovered and off the endangered species list", Daines said in a press release.
There used to be about 50,000 grizzly bears ranging over large parts of North America but their population dropped substantially in the 1850s due to widespread hunting and trapping.