Lucas Macaj: Everything We Know About Missing Hiker

A 23-year-old hiker has been missing for more than three days after he vanished while climbing in Rocky Mountain National Park in Colorado.

Lucas Macaj, from Colorado Springs, was last heard from Sunday afternoon, when he texted a friend to say he was at the summit of Longs Peak, according to Rocky Mountain National Park's social media statement.

He had started the Longs Peak Trailhead via the Keyhole Route earlier that day and reported missing by the evening, after "significant storms moved through high elevations" in the afternoon.

A search has been launched, including air reconnaissance, a heat-sensing fixed-wing flight and ground teams. A fixed-wing aircraft outfitted with infrared and color sensors and a Helitak crew, from the State of Colorado Department of Fire Prevention and Control, was used on Monday.

Authorities have scaled the Longs Peak Trail, the Ledges on the Keyhole route and the Boulder Brook Trail.

"He is likely wearing a dark-colored top, tan or brown pants, khaki-colored boots, and a black backpack. He may also be wearing a beanie and dark-colored gloves," park authorities said.

Macaj is described as 5-foot-9 and 155 pounds, with brown hair and green eyes. His car was discovered parked at the Longs Peak Trailhead on Monday.

Hundreds have commented on Rocky Mountain National Park's Facebook post, with many sending their thoughts and prayers for Macaj and his family.

Anyone who thinks they have any information that could help authorities find Macaj, or if they were at any of the areas being searched on Sunday, is asked to get in touch with the National Park Service (NPS). People can use the website, call 888-653-0009 or email [email protected].

The NPS said: "You don't have to tell us who you are, but please tell us what you know."

The missing hiker comes after three hikers died in one week in California. An unnamed climber was killed in the North Fork of Lone Pine Creek Trail, near Mount Whitney, on Sunday.

Three days earlier, the bodies of two missing hikers, identified as 28-year-old Andrew Niziol and 29-year-old Patty Bolan, were recovered from the north face of Mount Whitney.

That led to the Inyo County Sheriff's Office issuing a warning about hiking in "early spring conditions." Hikers were told to "stay together, turn around before deteriorating conditions become unmanageable, make responsible decisions, and be prepared and fit."