Sonic Drive-In Sonic Drive-In, 436 S. Broadway, Cortez, CO 81321 Local: (970) 565-3102 Visit Website Overview Amenities America's Drive-In. Designations: Colorado Restaurant Association Member, CRA ID Related Articles The Top Things to Do in Boulder 9 Ways to Savor "America's Foodiest Town" Things to Do with Kids in Boulder: Ideas by Age A Guide to Boulder’s Flatirons Scenic Drives from Boulder 10 Outdoor Adventures to Try in Boulder