Atlas ICBM Highway
The Dyess Air Force Base in Abilene was ringed by twelve Atlas Intercontinental Ballistic Missile silos in the early 1960s. Hwy 604 ran past five of them. There isn't much to see; the nuclear missile silos are all underground, and they've long been retired. But at several points along the 51-mile road there are reflective green road signs proclaiming it to be "The Atlas ICBM Highway."
The most convenient of these is in the town of Clyde, just south of I-20. Hwy 604 was officially given its designation in 2001, by a unanimous vote of the Texas state senate, which also recognized the Convair Atlas Intercontinental Ballistic Missile as "an awesome deterrent weapon system."