An aerial search is under way for a Colorado chiropractor missing during a solo climb of Mount McKinley in Alaska, North America's highest mountain.Denali National Park Service spokeswoman Maureen McLaughlin said there was no sighting of 41-year-old Gerald Myers of Centennial during a search on Thursday.According to a note left for his three climbing partners, Myers left their 14,200-foot camp around 4:30 a.m. on Tuesday. He was next spotted at a 17,200-foot high camp at approximately 11 a.m. the same morning, where he collected his skis and dug into a cache that the team had left on a previous acclimatization climb.He was last seen Tuesday afternoon as he climbed the ridge approaching McKinley's 20,320-foot summit. Park rangers at a high camp saw him making the traverse to Denali Pass at 18,600 feet and then again near 18,900 feet.A team traveling about two hours behind him did not see any signs of Myers as they approached the summit.He did not return to the camp at 14,200 feet, where his climbing partners were waiting. They said Myers took no sleeping bag, bivouac sack, stove to melt snow or thermal pad with him when he attempted to summit.At the time, weather high on the mountain was deteriorating with winds gusting 40 to 50 mph.Searchers did not know what route he planned to take down from the summit. Park rangers were using spotting scopes to look for him along the various descent routes.According to his partners, Myers was likely carrying his FRS "family band" radio as well as a SPOT locator beacon. Myers had programmed his SPOT device with three button settings: "OK, moving up," "OK, but not moving," and "911."According to the GPS data recorded by the SPOT, the last electronically recorded location was the 17,200-foot camp at 10:50 a.m. on May 19, when Myers had recorded his position by pressing the "OK, moving up" button.Throughout his trip, Myers had reportedly been making one position recording each day.Myers works at the Arapahoe Chiropractic and Acupuncture Center in Centennial."He was very excited about this trip," Kristin Garnett, a coworker, told the Anchorage Daily News. "He trained for this climb all season ... He talked a lot about the climb."His brother, Wayne Myers, told 7NEWS Reporter Lance Hernandez that Gerald had prepared for the climb several times before."I even went to live with him for awhile last year out in Colorado and he was preparing for it then, although I tried to tell him it wasn't such a hot idea to go by yourself to climb Denali, but he wouldn't hear that," Wayne Myers said."The article off your (Web) site as to where he didn't have his bivy sack and sleeping bag and all that, it just shocks me that he wouldn't have these things on such a climb," he said.Wayne Meyers called his brother "pretty much an expert" climber.According to the National Park Service, aerial searches will continue as weather allows.A neighbor of Myers in Centennial, Jill Mayer, told 7NEWS, "I can't imagine him giving up. He'll go until he gets what he wants and so if it's at all possible he'll get out of this."Another neighbor, Dagmar Borcic, said, "(Myers is) extremely smart, extremely athletic, and we just hope he comes home safely."