ROCKY MOUNTAIN NATIONAL PARK, Colo. (CBS4)– Brian Perri has been missing since he summited Mount Meeker in Rocky Mountain National Park on June 30. One of his friends is taking it upon himself to conduct his own search on the route he believes Perri took down from the mountain.

The 38-year-old man from Fort Collins texted a picture of his summit to the 13,911-foot mountain and that was the last communication anyone has had from him.

For the past four days, JC Fischer has been looking for his best friend, traveling to Mount Meeker and hiking for hours on end, hoping to find Perri or some clues as to what happened leading to his disappearance.

“We are exhausted and that’s to put it lightly,” said Fischer.

Search and rescue members in Rocky Mountain National Park say their search has encompassed significant sections of 22.5 square miles. Crews are using helicopters, ground crews and dog teams.

They’ve even added drones to their arsenal of search tools. Officials say the drone helps them view inaccessible terrain which is difficult to see from helicopters or by crews on the ground.

Fischer thinks more could be done, “They have been very caring but have not implemented the necessary tools to find him.”

Perri is an experienced hiker who was Special Ops in the Army and has specialized survival training.

“I would have this giant backpack and he would have this little hiking backpack and he would pull out a gallon Ziploc bag and say, ‘Whatever I can put in this little Ziploc baggie, I can survive 10 times longer than you,” said Fischer.

Rescue teams then found Perri’s car in the parking lot at the Sandbeach Lake Trailhead after they were notified on July 5.

Fischer thinks Perri was in a hurry to get down the mountain and may have taken a straight line down the mountain. That’s the area he has been searching and says he will continue to again and again.

“I’m going to be back out every single day until he comes home,” said Fischer.

A GoFundMe page has been set up to help with the cost of the rescue effort.

Park rangers would like to hear from anyone who has been in the Mount Meeker area since Saturday, June 30. Especially those who noticed abandoned gear or other clues. Please call (970) 586-1204.