Several special routes of U.S. Route 26 (US 26) exist. In order from west to east, they are as follows.
U.S. Highway 26 Business (US-26 Bus.) is a business route in and around the small town of Ririe northeast of Idaho Falls. It connects US-26 to the community as well as SH-48.
U.S. Route 26 Business and U.S. Route 22 Business in the Casper, Wyoming area is a concurrent business spur that goes from the intersection of US 20, US 26, and SR 257 in Mountain View to I-25 in Casper, following 1st Street and Yellowstone Street. It is also partially concurrent with I-25 Business and US 87 Business.
U.S. Route 26N (US 26N) existed from 1939 to 1959. It went east along today's L-62A, then south along today's US-385 to just north of Bridgeport and east along today's USâÂÂ26 to Broadwater. In those years, the mainline of USâÂÂ26 between Bridgeport and Broadwater went on the south side of the North Platte River, along today's N-92.