New Utah Highway Shortens Distance Between Zion Park and Grand Canyon

FOR the highway departments of Arizona and Utah this year is outstanding in marking the completion of two most important projects. We link the names of the two commonwealths for the good reason that their efforts have been united in closing the gaps which have heretofore effectually operated to obstruct direct communication between their major arteries of highway traffic.

In fact, we may say that this is the year in which highway dreams come true, if we assume that the completion of the Grand Canyon bridge is, like the building of the Zion Park Highway, the accomplishment of a long-considered objective.

By spanning the Grand Canyon on U. S. Route 89 the two states become neighbors in fact, as well as in geographical location; while, in conjunction with the bridge, the highway now being constructed between U. S. 89 and U. S. 91 via Zion Park will have far reach ing effects not only upon the routing of traffic between the two states but upon that originating in distant and much more populous communities.

It is especially noteworthy that in both instances engineering skill has worked its wonders in a region where the ages frown upon man's every attempt to destroy the barriers thrown across his pathway, and where nature defies the efforts of his noblest artistry to describe faithfully or depict on canvas her own masterpieces of form and color.

Unsurpassed and unique as the scenery of this canyon region admittedly is, it is from that very character that so many unusual difficulties and problems must be overcome in building highways in, through, or over these vast chasms The necessity of a road leading directly from Zion park to the Grand Canyon highway has been evident from the time that the motor vehicle first traversed the routes leading into the national parks of southwestern Utah. A tour which included Bryce Canyon, Cedar Breaks and Zion Park necessitated much retracement over the branch roads leading from the main highways, while a round-about route with many objectionable features as to grade and alignment extended from Zion Park to the Grand Canyon, where, prior to the construction of the bridge, farther

By H. V. RICHARDS, of Utah State Road Commission

progress into Arizona abruptly terminated.

Motorists from Arizona in traveling the new highway now nearing completion will reach Zion Park after a drive of over 125 miles over an improved road from the North Rim of the Grand Canyon at Bright Angel Point, as compared with 142 miles over the old route. From Zion Park to Bryce a drive of 149 miles will be reduced to 88 miles. The Zion-Mount Camel cut-off will be itself a scenic highway par-excellence, through a heretofore inaccessible region, and add much to the attractions of the tour.

The new highway has a total length of 24 miles. Eight and one-half miles within the limits of Zion Park are being constructed by the Bureau of Public Roads in cooperation with the National Parks Service, at an estimated cost of $1,500,000. The remaining mile age outside the park in Kane county is being constructed by the State as a federal aid project, at a cost of approximately $500,000.

The setting for the park section is Pine Creek Canyon, a deep and narrow gorge, walled in by the towering vermillion cliffs for which the park is famous.

In gaining elevation it has been necessary to cut a tunnel for the highway paralleling the face of the south wall of the canyon for a distance of 5,607 feet, by far the longest rural highway tunnel in the United States, or in any other country so far as record is obtainable.

Although set well within the cliff, as a protection against any subsequent slides and breakage, the tunnel section is by no means an interruption in the unfolding panorama of stupendous scenery. Six galleries lead from it to the outside-galleries that would lead into airy space were it not for the solid walls of masonry across the portals. From these vantage points views are disclosed that were never before available even to the most venturesome climbers, as the mountain through which the tunnel goes is quite unscalable.

Starting near the park checking station, the road turns to the east and immediately begins its ascent along Pine Creek. For four miles it spirals up the rock and talus slope of the south wall of the canyon in a series of safe grades and curves in making elevation to the base of the vertical cliffs, where it enters the tunnel in order to continue to gain elevation. The tunnel section is on a five per cent grade throughout. No grades on the new highway will exceed six per cent and will equal that rate on only short stretches.

There were several sections along the highway line that were inaccessible to the surveyors. For example, in surveying the tunnel position the engineers, we are informed by the Bureau of Public Roads, broke a foot-path along the base of the cliff. From this path, which was between two and three hundred feet below grade, the proposed tunnel site was determined.

The contractor, the Nevada Contracting Company of Fallon, Nevada, installed an aerial cableway 1000 feet long, from the creek bed to the base of the cliff in transporting men, materials and equipment to begin the tunnel operations. In several instances scaffolding was constructed up the face of the cliff to the tunnel elevation and the gallery openings cut through to line. Operations began at the west portal and subsequently from outside such galleries as could be reached. The east portal was inaccessible. As the galleries were opened ,a pilot tunnel eight feet by nine feet, was drifted both ways on the tunnel line and grade. Ring drilling followed the pilot tunnel closely and was kept well in advance of the full bore operations. Usually 17 holes were drilled for each ring and the rings were spaced about three feet apart along center lines. Each ring was loaded with 50 pounds of dynamite and 10 or 12 rings would be fired at one time. The full tunnel section is 22 feet wide and approximately 16 feet in height.

The use of the galleries greatly expedited all phases of the tunnel operations, air, light and water lines being brought into each gallery as needed. The galleries also facilitated the disposal of the rock excavation.

The tunnel was holed through at the east portal October 20, 1928. The floor is to receive some form of permanent surfacing, and light from the galleries will be supplemented by artificial illumination for the protection of traffic. Light and power for the tunnel operations were brought by a specially built line 20 miles in length.(Continued on page 47)