b'T R A N S P O R T A T I O NRailroadsThe Union Pacic Railroad runs north-south through the middle of the county, passing through Dubois, Spencer, and Humphrey.Major Interstates/Highways I-15 runs north-south between Idaho Falls in the south and Dillon, MT in the north. SH-22 runs southwest from Dubois to an intersection with SH-33 near Howe.Road and Bridge SystemClark County Road & Bridge oversees road and bridge construction and maintenance (unknown mileage of roads maintained).Airports Dubois Muni Airport (U41) - DuboisPublic TransportationThere is no public transportation in Clark County.326 I D A H O I N F R A S T R U C T U R E G U I D E B O O K'