State Highway 99 (SH-99) is a north–south state highway through central Oklahoma. It runs from the Texas state line at Lake Texoma to the Kansas state line near Lake Hulah. It is 241.5 miles (388.7 km) long. The highway overlaps U.S. Highway 377 (US-377) for over half its length.

State Highway 3, also abbreviated as SH-3 or OK-3, is a highway maintained by the U.S. state of Oklahoma. Traveling diagonally through Oklahoma, from the Panhandle to the far southeastern corner of the state, SH-3 is the longest state highway in the Oklahoma road system, at a total length of 615 miles (990 km) via SH-3E.