One of the pilots killed in the midair collision over Boulder on Saturday was Alexander Gilmer, 25, of Evergreen.
Gilmer was piloting a one-man Piper Pawnee when it collided with a Cirrus SR20 at about 8,000 feet at 12:45 p.m. He was identified as an employee of Mile High Gliding and a licensed pilot since 2003.
The occupants of the other plane, lawyer Bob Matthews of Boulder and engineer Mark Matthews of Englewood, both died.
Gilmer was towing a glider with a pilot and two passengers when the accident occurred. The glider and its occupants landed safely at Boulder Municipal Airport.
Scores of investigators from the National Transportation Safety Board were on the scene looking for clues on Sunday.