Rangers closed all entrances to Yellowstone National Park on Monday because of flooding, rockslides and "extremely hazardous conditions" inside the massive reserve, officials said.
Power outages have also plagued the 2.2 million-acre park, which includes portions of Wyoming, Montana and Idaho, officials said.
In the 24 hours before mid-day Monday, more than two inches of rain fell on several cities near Yellowstone, including Quadrant, Wyoming (2.68 inches); West Yellowstone, Montana (2.11 inches); Soda Butte, Montana (2.82 inches); and Gardiner, Montana (1.29 inches).
"With additional rainfall forecasted, the park does not want large numbers of day-use visitors stranded," according to a Yellowstone statement.
Park superintendent Cam Sholly said in a statement that efforts are underway to "evacuate the northern section" of Yellowstone because of "multiple road and bridge failures, mudslides and other issues."
Sholly added that much of Gardiner, Montana, on Monday was "isolated" and that officials "are working with the county and State of Montana to provide necessary support to residents, who are currently without water and power in some areas."
There's more rain in the forecast in the Yellowstone area before it dries out on Wednesday.
Flood watches are in effect for parts of Washington, northern Idaho and northwest Montana. Excessive rainfall in the region could lead to flooding of creeks, streams and other low-lying locations.
Unchecked climate change has been leading to more examples of radical weather, including an increase in floods.
