First responders are searching parts of the west side of Green Mountain late Friday night trying to find a downed hang glider.

West Metro Fire Rescue tweeted just before 10 p.m. that they were on scene in steep terrain and searching for the downed glider in the dark with light from a Flight for Life helicopter.

The hang glider called 911 himself around 8:30 p.m. and told dispatchers he was down.

This is a developing story. Stay with 9NEWS for updates as we work to learn more.