Farm to Market Roads in Texas are owned and maintained by the Texas Department of Transportation (TxDOT).
FM 500
Farm to Market Road 500 (FM 500) is located in San Saba County. It runs from SH 16 north of San Saba to FM 45 north of Richland Springs.
FM 500 was designated on July 13, 1945, from SH 16 northwestward to Fairview. It was extended northwest twice: a extension on November 23, 1948, and a extension on September 29, 1954. On September 28, 1955 (connecting section designated August 24), it was extended to the west to FM 45, replacing FM 1479.
RM 501
Ranch to Market Road 501 (RM 501) is located in Mason and San Saba counties. Its western terminus is at SH 71 in Pontotoc. It travels to the north before turning to the east toward Cherokee, where it crosses SH 16. It then travels eastward and then northeastward before reaching its eastern terminus at FM 580 southwest of Bend, for a total length of .
RM 501 was authorized on July 13, 1945, as Farm to Market Road 501 (FM 501), a road between SH 16 in Cherokee and the Salt Branch Road in San Saba County. On November 29, 1957, FM 501 was extended west to Pontotoc, replacing FM 1648; at this time, the designation was changed from FM 501 to RM 501. On October 31, 1958, RM 501 was extended eastward . On September 27, 1960, it was extended to its junction with FM 580.
FM 502
Farm to Market Road 502 (FM 502) is located in McCulloch and San Saba counties.
FM 502 was designated on July 14, 1945, from US 377 southeast and east via Mercury to the Milburn Road. On September 24, 1954, FM 502 was extended east to the McCulloch–San Saba county line. On October 1, 1954, the route was extended southeast to FM 45, replacing FM 2048.
FM 503
Farm to Market Road 503 (FM 503) is located in McCulloch and Coleman counties. It runs from US 87 northwest of Melvin to a point north of SH 153 northwest of Coleman.
FM 503 was designated on July 14, 1945, from a point on US 87 northwest of Melvin, northward miles to Salt Gap. On November 23, 1948, the FM 503 designation was extended miles to the north, to Doole. On November 21, 1956, the route was extended northward to Stacy. On September 27, 1960, the road was extended north to the McCulloch–Coleman county line. A northward extension on October 14, 1960, connected FM 503 to US 67, as a replacement for FM 566. On May 6, 1964, FM 503 was extended north to FM 53 (now SH 153). On May 7, 1974, FM 503 was extended north to its current terminus.
FM 504
Farm to Market Road 504 (FM 504) is located in McCulloch County.
FM 504 was designated on July 14, 1945, from US 283 west and south through Lohn to a point east of Pear Valley. On July 21, 1949, FM 504 was extended west . On May 23, 1951, FM 504 was extended west through Pear Valley to a road intersection. On November 20, 1951, FM 504 was extended west . On December 17, 1952, FM 504 was extended west miles to FM 503.
RM 505
Ranch to Market Road 505 (RM 505) lies entirely within Jeff Davis County in the Trans-Pecos region of far West Texas. Intended to provide a link between the county's only two incorporated areas, Valentine and Fort Davis, RM 505 begins at a junction with US 90 south of Valentine and travels about east to an intersection with SH 166 approximately west of Fort Davis.
FM 506
Farm to Market Road 506 (FM 506) is located in Willacy and Cameron counties. It runs from Bus. US 77 in Sebastian to US 281 and overlaps SH 107 in Santa Rosa.
FM 506 was designated on July 3, 1945, from Santa Rosa to a point north. On November 23, 1948, the road was extended to US 77 (later Loop 448, now Bus. US 77) in Sebastian. On October 26, 1954, a section from SH 107 in Santa Rosa to US 281 was added, creating a concurrency with SH 107.
FM 507
Farm to Market Road 507 (FM 507) is located in Cameron and Willacy counties. It runs from Bus. US 77 to FM 498.