US 81 begins at an interchange with I-35W/US 287 in northern Fort Worth. The two highways travel northwest as a freeway, passing by the Bureau of Engraving and Printing near Blue Mound Road, through the city's northwest side. US 81/US 287 leaves the city of Fort Worth and enters Wise County near Avondale. The highway runs through or near the towns of Rhome, New Fairview, Decatur, Alvord, and Sunset before separating in southern Bowie. US 81 runs through the town as Wise Street, running in a more east–west direction before turning in a more north–south direction at FM 174. The highway has a mostly rural route, running through western Montague County, before crossing the Red River into Oklahoma.
History
US 81 at its inception in 1926 followed the route of State Highway 2, which began in Laredo and passed through San Antonio, Austin, Waco, and Fort Worth before passing over the Red River into Oklahoma north of Ringgold. The 1936 Official Map of the Highway System of Texas clearly shows the route labeled both as US 81 and SH 2. It was cosigned with US 83 for from Laredo to south of Webb, with US 79 for from Austin north to Round Rock, and with US 77 for from Waco to Hillsboro. In 1940 US 287 was extended south into Texas, and a stretch from Fort Worth northwest to Bowie was cosigned with US 81. The summer 1941 Texas Highway Map shows this pairing, and the current southern terminus of US 81 is still cosigned with US 287. The spring and summer 1949 Texas Highway Department Official Map designates the length of US 81 from Laredo to Fort Worth as part of the National System of Interstate Highways, but no numeric designation was given at the time. It was not until 1959 that parts of US 81 in Texas appeared on the Texas Official Highway Travel Map cosigned with I-35 shields. Succeeding maps reflect the slow completion of I-35 and I-35W over the stretch of US 81 between Laredo and Fort Worth, with the 1978-79 Texas Official Highway Travel Map showing only a section from Encinal north to south of Artesia Wells as incomplete, and the 1980 Texas Official Highway Travel Map shows that section completed. In 1980, US 81 was cosigned with I-35 and I-35W except where the Interstate bypassed towns; US 81 provided the main route through town and then reconnected with I-35 on the other side. The longest section of US 81 in 1980 not cosigned with the Interstate ran from I-35 in Hillsboro north to I-35W, just north of Grandview. This section of US 81 became SH 81 in 1991 when most of US 81 in Texas was decommissioned. The section of highway from Devine to Lytle became SH 132 and the section from Derby to the Pearsalltown square became Spur 581 when US 81 south of Fort Worth was decommissioned in 1991.
