Interstate through the Virgin River Gorge opened in 1973

                                             The Virgin River Gorge opened in 1973.

IT is probably the curviest portion of I-15 anywhere -- the Virgin River Gorge -- and it opened in the winter of 1973.
This 29 1/2 mile section of interstate highway is taken for granted today, but it saves some 45 minutes in travel time over the old route -- and believe it or not, it is considered a safer route than its predecessor,  the "Utah Hill" (or "Old Highway 91), that started in Santa Clara and ended up in Beaver Dam, Arizona.
In fact, that old stretch of highway produced 23 fatalities just between 1968 and the Virgin River Gorge opening five years later.
The Virgin River Gorge section of I-15 was dedicated on Dec. 21, 1973 (and had opened to traffic a week or so prior).
According to the Iron County Record newspaper of Dec. 20, 1973, it was the most expensive stretch of rural interstate highway ever built at the time -- costing $61 million (or almost $337 million in 2017 dollar values).

                   The Virgin River Gorge is mountain grades and curves.

An engineering marvel, the highway passed through some sections of gorge that were only 150 feet and others with 2,000-foot high mountain cliffs rising up.
This section of I-15 directly connects St. George, Utah with Littlefield, Arizona.
Governor Calvin L. Rampton said during the highway's dedication that Arizona State officials had to be greatly credited for their help on the highway construction. Even though it was a landlocked portion of their state where the road went, Arizona was a key component in its completion.
The highway stretch's completion also required assistance from Nevada -- a rare three state effort.
Flashfloods and quicksand in the Gorge made construction difficult. It required more than 4 years of work, plus 5 bridges over the Virgin River and 12 places where the river had to be rerouted to accommodate the roadway.
A helicopter pilot was killed in 1969 after he crashed in the Virgin River Gorge while doing survey work there. A special dune buggy was brought in from Texas to aid in the surveying of the Gorge.
Although ALL of the Gorge is NOT in Utah, the Utah Department of Transportation often does a lot of the maintenance on the freeway there, for Arizona.

              The Virgin River Gorge section of I-15 is an engineering marvel.