A record number of people watch sheep cross Highway 55 in Idaho Every spring Frank Shirts leads his flock of sheep from Wilder into the foothills north of Boise where they will feast on the grass during the summer. and last updated 2021-04-17 20:29:33-04 EAGLE, Idaho â Every spring Frank Shirts leads his flock of sheep from Wilder into the foothills north of Boise where they will feast on the grass during the summer. But to make this journey, they have to cross Highway 55, and that gives people an opportunity to check out this Idaho tradition. "This is just absolutely amazing, you know you are back in the west when they shut down a major highway so sheep can cross a major highway," said Scott Rand, who witnessed the crossing for the first time with his wife Rebecca. "It is surreal.â