The Tahoe Backcountry Vertical Challenge continues this winter for the third year. Participants must register online to log human-powered, backcountry vertical travel. It’s all free.

When the cumulative goal of 15 million vertical feet of human-powered uphill travel is reached, Alpenglow Sports of Tahoe City will make a $3,000 donation to the Sierra Avalanche Center.

This is the opportunity for local backcountry enthusiasts to give back to the Sierra Avalanche Center at zero cost. Every single foot of uphill travel matters, and no number is too small.

The event runs through April 30.