Farm to Market Road 51 or FM 51 is a Texas state road that runs from Gainesville south and west to an intersection with US 67 in Somervell County. Skirting the northwestern fringes of the Dallas-Fort Worth Metroplex, it is available as a more scenic and less-congested shortcut between I-20

Interstate 20 in Texas

Interstate 20 in Texas is a major east–west Interstate Highway in the Southern United States, running east from a junction with Interstate 10 east of Kent, Texas, through the Dallas-Fort Worth Metroplex to the border with Louisiana near Waskom, Texas...

 west of Weatherford and I-35

Interstate 35 in Texas

Interstate 35 in Texas is a major north–south Interstate Highway running from Laredo near the United States-Mexico border to the Red River north of Gainesville where it crosses into Oklahoma. Along its route, it passes through the cities of San Antonio, Austin, and Waco before it splits into two...

 north of Gainesville.

History

This route north of Weatherford was SH 89 until 1939.
FM 51 was designated in 1942 from Gainesville to Era

Era, Texas

Era is an unincorporated community in Cooke County, Texas, United States.About 7 miles west of Era, there is the Liberman Broadcasting Tower Era, one of earth's tallest structures, and as of May 2007 was the tallest structure in Texas. The tower is named for its proximity to Era, though it is much...

. Less than a month later, three more sections were added: one from Decatur

Decatur, Texas

Decatur is a city located in Wise County, Texas, United States. This city was named after Stephen Decatur, Jr. The population was 5,201 at the 2000 census. A July 1, 2008 U.S. Census Bureau estimate placed the population at 6,432. It is the county seat of Wise County...

 northeast 4.8 miles, one from SH 114 to Springtown

Springtown, Texas

Springtown is a city in Parker County, Texas, United States. The population was 2,062 at the 2000 census.-Geography:Springtown is located at ....

, and one from Weatherford, Texas

Weatherford, Texas

Weatherford is a city in Parker County, Texas, United States, and a western suburb of Fort Worth. The population was 19,000 at the 2000 census. It is the county seat of Parker County and is part of the Dallas-Fort Worth Metroplex.-Geography:...

 north 4 miles. In 1944, it extended from 4 miles north of Weatherford to Springtown and from 4.8 miles northeast of Decatur to the Denton/Wise county line, closing one gap and partially closing another. In 1945, it extended south to Granbury

Granbury, Texas

Granbury is a city in Hood County, Texas, in the United States. As of the 2000 census, the city population was 5,718. It is the county seat of Hood County and the principal city of the Micropolitan Statistical Area....

. In 1947, it extended from SH 114 to Decatur, closing another gap. In 1949, it extended from the Denton/Wise county line to Era, closing the last gap. 5 months later, it extended east from the old location of US 77 to the new location of US 77. In 1953, it extended southwest to a road intersection 4.7 miles southwest of Granbury, replacing FM 1657. In 1956, it extended southwest to FM 201 (now FM 56). In 1959, it extended east from US 77 along the old location of US 82 to US 82. In 1985, it extended southwest to US 67, replacing FM 204. In that same order, FM 56 replaced FM 201.

Junction list

County	Location	Mile	Junction	Notes
Cooke Cooke County, Texas As of the census of 2000, there were 36,363 people, 13,643 households, and 10,000 families residing in the county. The population density was 42 people per square mile . There were 15,061 housing units at an average density of 17 per square mile...	Gainesville	0.0		Northern terminus
		3.2
	Era	12.9
Denton Denton County, Texas Denton County is a county located in the U.S. state of Texas. In 2000, its population was 432,976; in 2009 the estimated population had reached 628,300. Part of the Dallas – Fort Worth Metroplex, it is one of the fastest-growing counties in the United States. The county seat is Denton. The county...				No junctions
Wise Wise County, Texas As of the census of 2000, there were 48,793 people, 17,178 households, and 13,467 families residing in the county. The population density was 54 people per square mile . There were 19,242 housing units at an average density of 21 per square mile...		25.0
		28.7
	Decatur Decatur, Texas Decatur is a city located in Wise County, Texas, United States. This city was named after Stephen Decatur, Jr. The population was 5,201 at the 2000 census. A July 1, 2008 U.S. Census Bureau estimate placed the population at 6,432. It is the county seat of Wise County...	38.1
		39.1
		39.7
		45.2
		49.0		North end of SH 114 concurrency
		50.3		South end of SH 114 concurrency
		51.7
		55.1
Parker Parker County, Texas As of the census of 2003, there were 98,495 people, 31,131 households, and 24,313 families residing in the county. The population density was 98 people per square mile . There were 34,084 housing units at an average density of 38 per square mile...	Springtown	59.7
	Weatherford	74.7
		75.7
		77.1
		78.0
		80.2
Hood		91.9
	Granbury	100.4		North end of FM 4 concurrency
		100.9		South end of FM 4 concurrency/East end of Bus 377 concurrency
		101.3		West end of Bus 377 concurrency/North end of SH 144 concurrency
		101.6		South end of SH 144 concurrency
		102.0
		110.6		North end of FM 56 concurrency
		111.4		South end of FM 56 concurrency
	Paluxy Paluxy, Texas Paluxy is an unincorporated community in Hood County, Texas, United States.The community is located on Farm to Market Road 51, fifteen miles southwest of Granbury. It was part of Erath County until 1866, when Hood County was created....	116.2		North end of FM 205 concurrency
Somervell Somervell County, Texas There were 2,438 households out of which 37.40% had children under the age of 18 living with them, 61.70% were married couples living together, 9.60% had a female householder with no husband present, and 24.50% were non-families. 21.30% of all households were made up of individuals and 9.20% had...		118.1		South end of FM 205 concurrency
		123.9		Southern terminus

Note that the total mileage when listed by junctions does not agree with the total mileage certified by the Texas Department of Transportation

Texas Department of Transportation

The Texas Department of Transportation is a governmental agency in the U.S. state of Texas. Its stated mission is to "work cooperatively to provide safe, effective and efficient movement of people and goods" throughout the state...

because the number given by TxDOT does not include concurrencies.