Interstate 15 (I-15) is a major transcontinental north-south highway in the western United States that extends more than 1,470 miles through the states of California, Nevada, Arizona, Utah, Idaho, and Montana. It's the principal artery linking coastal ports to inland population centers and connects with the nation’s three transcontinental east-west highways: Interstate 10, Interstate 80 and Interstate 90.

On its route northward, Interstate 15 passes through the Virgin River Gorge of Mohave County in northwest Arizona. The gorge connects the southwestern rim of the Colorado Plateau and the northeastern edge of the Mojave Desert.

The south portion of I-15's route was built close to the alignment of the old US Route 91 (US 91), but the northern section, through the Virgin River Gorge, was built along road less terrain. The southern section of the highway was completed and opened in the early 1960s, but the gorge section was inaccessible until 1973.

Even before its opening, I-15 through the Virgin River Gorge was promoted as the most scenic highway in Arizona and today I-15 through the Virgin River Gorge is listed among the national exceptional engineering features of the federal highway system for its scenic wonder through a 500 million-year-old gorge. "Somehow," Arizona Highways magazine said in 1988, construction of I-15 "enhanced rather than distracted from nature's handiwork.".

The Virgin River was rechanneled 12 times in what became the most expensive rural highway project in the nation, at a cost of approximately $10 million-per-mile ($51.5 million in 2012 dollars). It still remains one of the most expensive and spectacular engineering feats in the rural interstate system.

Despite being isolated from the rest of Arizona, in the remote Arizona Strip, and only a 29.43 mile stretch of I-15, it remains notable for its scenic passage through the Virgin River Gorge. The highway heads in a northeasterly direction from the Nevada border northeast of Mesquite, Nevada, to the Utah border southwest of St. George, Utah.

The Old Spanish Trail from southern California had two routes through northwestern Arizona, splitting at Littlefield; one went north towards central Utah, and the other went northeast through the Virgin River Gorge, straddling the state line to the Four Corners area. When the Arrowhead Trail was marked in the 1920s and US Highway 91 in 1926, automobile travelers between Nevada and Utah followed the northerly route, turning east on US 91 in Utah to reach St. George.

Federal authorities decided to save 12-miles over US 91 when planning the Interstate and selected a route through the Virgin River Gorge to take advantage of its scenery and lower grades for trucks. Construction was completed first on the portion between Nevada and the gorge in the early 1960s. The bridges over Big Bend Wash were completed in 1962. The bridge over the Virgin River near Littlefield was completed by 1964. By 1965, the overpass over Black Rock Road (northward) was finally complete.

Construction through the gorge was slower and much more difficult, and the Virgin River segment wasn’t fully operational until December 14, 1973. To help speed along construction, the state of Utah loaned a portion of its allocated federal highway funds to Arizona.

The highway is of little importance to the transportation needs of Arizona, since it doesn’t link many Arizona communities, but serves a vital link between Salt Lake City and Las Vegas; and Los Angeles to the southwest.

Today the Arizona Department of Transportation traffic volume on I-15 through the Virgin River Gorge is 23,000 vehicles daily of which 39-percent are trucks.

Despite the extra funding, however, significant challenges remained. Flash flooding and quicksand in the gorge repeatedly caused problems, with equipment and materials disappearing overnight. Worse, the project claimed a life, when in October 1969, a helicopter performing reconnaissance on the gorge crashed due to winds, killing the pilot. To help navigate the gorge's rugged and unforgiving terrain, a special piece of equipment called a swamp buggy had to be brought from Texas. Even with its help, the route still demanded construction of four-bridges over the Virgin River. The western most bridge and the bridge carrying the northbound lanes at the third bridge location from the west were completed in 1972. Finally, in 1973, all five bridges were complete.

Max S. Blazzard, a 29-year veteran of the Arizona Department of Transportation said, the project was “the highlight of my highway career.”

And no wonder.

Eleven miles of the highway from the mouth of the Virgin River Gorge, northward to Black Rock Gulch, were the most difficult to construct of the 29.43-miles. As I-15 winds through the lower Virgin River Gorge, the canyon is only one-hundred fifty feet wide in some locations and vertical rock walls extend three-hundred to five-hundred feet high between mountain peaks that extend over two-thousand feet. The Virgin River Gorge section of I-15 includes six river crossings and required twelve channel re-locations.

The project was not without its problems.

On September 22, 1970, Jimmie Hughes of St. George was driving a short-bed dump truck in the Virgin River gorge, a few miles south of Cedar Pockets, when it went off a fifteen-foot embankment and crashed. Jimmie suffered head injuries and died shortly afterward. He left a family of nine children and a wife, who was eight and a half months pregnant.

After his wife, Ila May gave birth, they named the baby, Jimmie in honor of his father. Today he serves as a member of the St. George City Council.

Dixie High School in St. George, donated $2,000 to the family at the time of Jimmie’s death, due in large part because two children and a foster daughter of Jimmie and Ila May were attending the school at the time of the accident, according to Denise Hughes, one of Jimmie and Ila May’s sons.

In addition, a number of I-15 construction workers donated a significant amount of money to the family in their time of need.

“It really touched our family,” Denise said. “I was really grateful to my class (DHS Class of 1973) for their generosity.”

The 29.43-mile section of I-15 between St. George and Littlefield were completed on December 14, 1973.

During the 1970s, the Bureau of Land Management constructed a campground at Cedar Pockets and the Arizona Department of Transportation built a rest area. This rest area was turned over to the Bureau of Land Management in 2002 which maintains the nearby Virgin River Gorge Recreation Area. The rest area was closed but the campground continues to serve visitors to this unique area.

E-mail loren.webb@kcsg.com.