Minnesota mountaineer Lonnie Dupre has apparently completed a solo summit of the 20,237-foot Mount McKinley in January, the first time anyone has accomplished such a feat, according to Stevie Plummer, Dupre's expedition manager.

It was Dupre's fourth attempt at a January solo summit. He arrived at base camp to begin his journey on Dec. 18.

On Dupre's Facebook page Sunday afternoon, an image showing Dupre's latitude and longitude based on a GPS tracker he was carrying with him was accompanied by the exclamation "SUMMIT!!!!!"

The image also included a message from the climber, which said, simply, "All OK, Doing Well."

Plummer said she received the GPS SPOT tracker image at 2:08 p.m. (AST). Plummer was not actually able to speak with Dupre, though -- she said his satellite phone appears to not be working correctly.

"The last time I spoke with him he was at about 14,000 feet. He sounded extremely positive, ready to go (and) mentally drained," Plummer said Sunday prior to boarding a plane to Alaska.

Dupre expressed some of the mental strains of the expedition so far in a message to his support team, which he sent Thursday from an elevation of 14,200 feet.

"I have currently been on the mountain for 21 days and I wanted to talk a little bit about the psychological difficulties you have on a trip like this," Dupre said in a voice message from his satellite phone. "Mainly it is just the waiting for good weather so you can move. There is nothing worse than having to stay put, especially when you have 18 hours of darkness every evening; it makes for very long nights. And of course, always having the weather pull the rug out from under you when you were excited to go out somewhere that day and do some climbing. And then of course there is always worry about safety and supplies, and those kinds of things are the kind of things that weigh on my mind each day."

He ended the message by thanking his support crew and signing off with an "over and out."

Plummer said she was unsure when exactly Dupre began ascending from 14,200 feet to his camp at 17,200 feet because he was unreachable. But on Saturday, she received a GPS tracker message saying he had reached the 17,000-foot marker.

"Most people will spend about a day at 17,000 feet to acclimate," Plummer said.

According to Plummer, the hardest part of Dupre's journey will be the descent. By that point, she said, climbers are "extremely fatigued" and need to be "extra careful with their footing."

Dupre had apparently already started his descent Sunday night, with another GPS signal putting him back at 17,200 feet, according to a Facebook post at 6:20 p.m.