A 26-year-old woman from Boulder, Colorado, died after falling approximately 500 feet while free-solo climbing a ridge in the state's Rocky Mountain National Park on Sunday, the park said.

The unidentified woman's 27-year-old climbing partner called park rangers to report his partner had fallen from Blitzen Ridge on Ypsilon Mountain, the National Park Service said in a release Monday.

Free-soloing is a risky rock climbing technique in which climbers ascend without ropes, assistance or safety equipment -- leaving them without protection in case of a fall.

Search and rescue team members reached the uninjured climbing partner Sunday night, though his location required them to request the assistance of the Colorado Air National Guard, the park said. A helicopter from Buckley Air Force Base was used to hoist the man out.

Early Monday, a search and rescue team hiked the area above Ypsilon Lake to prepare for a helicopter recovery of the woman's body, according to the release. The body was then flown to another part of the park and then transferred to a medical examiner's office, which will determine the cause of death, the release reads.

This is the second reported death in Rocky Mountain National Park this month. A 25-year-old man died last week after falling and being pulled underwater at the park's West Creek Falls.