While you might still think of Lyft primarily as a ridesharing company, it also has the largest bike-sharing network in the country -- thanks to its Motivate acquisition last summer. To celebrate Earth Day and promote its carbon-free transport, the company is offering free bikeshare rides on Monday, April 22. You'll be able to hop on a free bike in New York City, Washington, DC, Chicago, Minneapolis, Columbus, OH and Portland, OR. But each city will handle the promotion slightly differently, so check in with your local network before you plan to ride.