The crash was reported around 7:12 a.m. near Horsetooth Cliffs Way and South Centennial Drive.
Police said the crash involved a silver hatchback that rolled off the side of the road and landed at the base of the reservoir.
One person was pronounced dead. It is unclear if anyone else was involved in the crash.
The victim’s identity will be released by the coroner’s office following notification of next of kin.
The cause of the crash is under investigation.