To protect the movement of wildlife impeded by busy roadways, a series of manmade overpasses and underpasses throughout the United States helps animals big and small safely get across the street, preventing collisions and saving lives. About 1,500 of these structures already have been built. Correspondent Conor Knighton looks at how they have protected genetic diversity in animal populations while also greatly reducing roadkill. He also visits the site of the Wallis Annenberg Wildlife Crossing near Los Angeles, which when complete will help cougars cross one of the busiest highways in the country. "CBS News Sunday Morning" features stories on the arts, music, nature, entertainment, sports, history, science and Americana, and highlights unique human accomplishments and achievements. Check local listings for CBS News Sunday Morning broadcast times. Subscribe to the "CBS News Sunday Morning" YouTube channel: null Get more of "CBS News Sunday Morning": https://cbsn.ws/1PlMmAz Follow "CBS News Sunday Morning" on Instagram: https://instagram.com/cbssundaymorning/ Like "CBS News Sunday Morning" on Facebook: https://facebook.com/CBSSundayMorning Follow "CBS News Sunday Morning" on Twitter: https://twitter.com/CBSSunday Subscribe to our newsletter: https://cbsnews.com/newsletters/ Download the CBS News app: https://www.cbsnews.com/mobile/ Try Paramount+ free: https://paramountplus.com/?ftag=PPM-05-10aeh8h For video licensing inquiries, contact: licensing@veritone.com