Texas State Highway 66

State Highway 66
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Route information
Maintained by TxDOT
Length:	35.0 mi (56.3 km)
Existed:	by 1933 – present
Major junctions
Southwest end:	SH 78 at Garland
Northeast end:	US 69/US 380 at Greenville
Location
Counties:	Dallas, Rockwall, Collin, Hunt
Highway system
Highways in Texas Interstate US State Toll Loops Spurs Park Rec FM ← US 66 US 67 →

State Highway 66 or SH 66 is a state highway running from Garland to Greenville, roughly parallel to Interstate 30. Along the way, it passes through Rowlett, Rockwall, Fate, Royse City, and Caddo Mills. It also twice crosses Lake Ray Hubbard.

History

SH 66 was previously designated first in 1926 as a route from Bogata northeast through Clarksville toward the Oklahoma town of Idabel. By 1931, this route had been added as a northern extent of SH 37, and was instead assigned along an ambitious route spanning the entire state from Wichita Falls to the Rio Grande near Hidalgo. In 1939, this entire second route was cancelled in favor of U.S. Highway 281.

The current route was designated in 1961, replacing FM 7 and U.S. Highway 67, which was rerouted atop I-30.

Junctions

County	Location	mi	km	Destinations	Notes
Dallas	Garland	0.000	0.000	SH 78 – Dallas, Sachse
	Rowlett	4.4	7.1	Pres. George Bush Tpk. – Richardson, Dallas
Rockwall	Rockwall	10.3	16.6	SH 205 – Lavon, McLendon-Chisholm
		11.5	18.5	FM 1141
		13.0	20.9	FM 3549
	Fate	15.1	24.3	FM 551
	​	18.1	29.1	FM 552 – Rockwall
	​	18.3	29.5	FM 1138 – Nevada
	Royse City	19.6	31.5	FM 548 – McLendon-Chisholm, Forney
Collin		20.5	33.0	FM 1777 – Josephine
Hunt	​	22.8	36.7	FM 2642 – Royse City
	Caddo Mills	27.3	43.9	FM 1565 – Union Valley
		27.6	44.4	FM 6 – Josephine
		28.2	45.4	FM 36	Southern end of FM 36 concurrency
		28.3	45.5	FM 36 – Floyd	Northern end of FM 36 concurrency
	​	33.2	53.4	FM 1570 – Greenville, L-3 Communications
	​	33.6	54.1	FM 3211
	Greenville	35.0	56.3	US 69 / US 380 – Denison, McKinney
1.000 mi = 1.609 km; 1.000 km = 0.621 mi