TELLURIDE, Colo. -- For the second time in two months, a hiker has been killed by a rockslide on El Diente Peak in the San Juan Mountains, authorities said.

John Merrill, 30, was killed Sunday by a massive rockslide as he hiked with his dog, Telluridewatch.com reported Monday.

Merrill was on south face of the 14,159-foot peak when the slide hit, the website said.

Another hiking party witnessed the accident and ran to Merrill, but he already was dead from major head trauma, San Miguel County Sheriff Bill Masters told the Montrose Daily Press.

Merrill had called his pregnant wife when he was about one hour from the summit of El Diente, County Coroner Bob Dempsey told Telluridewatch.com.

El Diente, which is Spanish for "the tooth," was Merrill's fifteenth summit of a peak over 14,000 feet, the website said. Masters said it was unclear whether Merrill had reached the summit and was descending when the slide hit.

Search and rescue team members retrieved his uninjured dog, a malamute mix, Telluridewatch.com said.

A similar rockslide in the same area killed retired Army Col. Peter Topp, 59, and seriously injured two of his hiking companions on July 26, Dempsey said.