The couple was on the Bear Creek Trail on Flagstaff Mountain when the bolt struck him around 1 p.m., according to the Boulder County Sheriff's Office. Another hiker spotted the couple an alerted authorities.
Initial investigations from the scene show that the man was struck directly in his upper body, and his wife was injured from "ancillary electrical current from the strike that hit her husband," the sheriff's office said.
She was conscious and breathing and taken to a nearby hospital with non-life-threatening injuries. The man was temporarily resuscitated on scene but died at the hospital.
The identities of the man, 36, and his wife, 37, are being withheld pending notification of their families.