A man exploring an Oregon national park fell more than 600 feet into a volcanic crater, the Crater Lake National Park said.

On Monday afternoon, the Coast Guard Sector North Bend received a call that a man was injured inside the Crater Lake caldera at the Crater Lake National Park.

When the Coast Guard arrived, a helicopter rope team was already 600 feet down into the crater and could hear the man yelling for help but couldn't reach him, according to a Coast Guard press release. The Seattle Times reports that the man fell 800 feet into the crater.

A Coast Guard aircrew safely hoisted the man out of the crater before taking him to a nearby parking lot where he was transferred to a medical helicopter and taken to the hospital.

The man, whom authorities have not identified, suffered unspecified injuries. His condition is unknown at this time.

Crater Lake is 1,943 feet deep, making it the deepest lake in the United States and the ninth deepest in the world, according to the National Park Service. It formed more than 6,800 years ago when the Mount Mazama volcano collapsed.

The crater is now half filled with water and is the main feature of the Crater Lake National Park.