A group of mountaineers were battling through the icy wilderness as they climbed Mexico’s highest peak when they spotted dark skulls and withered hands emerging from the snowy landscape—an almost unbelievable sight. The scene was shocking enough, but when rescue workers arrived to excavate, they uncovered an even more astonishing secret buried deep under the snow: two mummified bodies locked in an embrace, believed to be hikers who went missing in a 1959 mountaineering disaster.

AP photos show the wind-eroded, skeletal remains—dubbed the “frozen mummies”—initially appearing as a single skull and hand, thought to belong to one person. But further digging revealed that the skull and hand actually belonged to two different individuals. Their light red clothing, muscles, and internal organs had nearly disintegrated. Investigators believe the two may have been embracing each other at the time of their deaths.

The incident occurred on Pico de Orizaba, Mexico’s highest peak and the third tallest in North America. It is also a renowned national park with numerous climbing routes that attract many hikers. Local official Juan Navarro believes the mummies are linked to three hikers who went missing on November 2, 1959. He speculates that a third body may soon be discovered. After excavation, DNA testing will be conducted in hopes of returning the remains to their families and finally solving this long-standing mystery.