The event begins at 7 a.m. Tuesday with on-site registration, followed by a moment of silence at 8:46 a.m. The climb starts at 9:03 a.m. and runs until noon.
Last year, men, women, children and firefighters in full gear participated.
This stair climb is one of 40 that are held around the world on Sept. 11. The one in Red Rocks is the largest in the country. The event raises funds for FDNY Counseling Services Unit and programs provided by National Fallen Firefighters Foundation.