PHILADELPHIA -- Ever since he turned 50, Mark Gibson has been challenging himself to do one crazy thing every year.
He has run from Pittsburgh to Philadelphia and rode a skateboard from Washington, D.C. to Ottawa, Canada.
Now, at 60 years old, he's tackling what he calls the Rocky Mountain Everest Challenge.
The challenge is his attempts to run the equivalent from sea level to the top of Mt. Everest and then back down to sea level again on the famous Rocky steps at the Philadelphia Art Museum.
That's up and down the stairs 880 times. He's doing the challenge to raise money for Alex's Lemonade Stand to help the fight against childhood cancer.