A Three Million Dollar Automo 

 bile Scenic Highway 



By Fred AV. ^ incent 



HIGH masonry walled roadways 

 clinging to precipitous mountain 

 sides and so cunningly built that 

 no cement enters into their composition ; 

 bridges of solid concrete spanning deep 

 mountain gorges, and tunnels through 

 living rock are only a few of the fea- 

 tures of the Columbia Highway, a two 

 hundred mile three million dollar road- 

 way that Oregon is rapidly driving 

 through the heart of the Cascades and 

 Coast Range mountains, down the Col- 

 umbia River, from The Dalles to the 

 Pacific Ocean. 



For two years the work has been un- 

 derway, guided by engineering experts 

 who first spent months in Europe study- 

 ing the famous motmtain roadways there 

 with the sole object of not duplicating, 

 but of bettering the best the Old World 

 had to ofifer. 



From the Dalles, where it connects 

 with the trunk roads leading into the in- 

 terior and the East, the highway follows 

 the south bank of the Columbia — second 

 largest river in the United States — and 

 plunges into the rugged and picturesque 

 Cascade i\Iountains. Here on one side 

 for more than fifty miles is the river, 

 on the other a rock wall rising sheer 

 for heights varying from a few hun- 

 dred to thousands of feet. It is through 

 this majestic water carved gorge that 

 the engineers faced and solved their 

 hardest problem. 



Their instructions were to build a 

 roadway not less than twenty- four feet 

 in width and with a grade not to ex- 

 ceed five percent at any point. A rail- 

 road had possession of what little shor- 

 ing there Avas along the river, and for 

 this reason the construction force faced 

 miles on miles of clififs, long reaches of 

 slope deep Avith slide rock, and a tim- 

 bered wilderness with earth pitched 

 ready to slip. 



The first work called for tunnels and 

 the highway builders were compelled to 



make several bores through imposing 

 rock points that rushed skyward hun- 

 dreds of feet as straight as a plumb line. 

 r)ne tunnel at "Storm Point" is more 

 than three hundred feet long. To insure 

 proper light, arches have been cut 

 through on one side to overlook the 

 river at regular intervals. 



Here in the mountains has been 

 worked into perfection the ancient art of 

 dry masonry wall construction. There 

 are approximately two miles of the high- 

 way built atop such wall work and all 

 along steep mountain sides. In them 

 each stone was cut to fit and to stay for 

 all time where put. 



Instead of the usual steel, reinforced 

 concrete was resorted to in building the 

 bridges that span the numerous tor- 

 rents. One spanning Mofifat Creek is 

 the largest flat arch monolithic bridge in 

 America and the largest three-hinged 

 arch in the world. The clear space of 

 the span is one hundred and seventy feet 

 and the arch rises only seventeen- feet 

 in that distance. Another bridge that 

 crosses over a canyon two hundred feet 

 in depth is three hundred and sixty feet 

 long. 



One of the biggest problems was en- 

 countered in the construction of the high- 

 way over slopes where slides threatened. 

 This included work over an immense bed 

 of broken lava rock so restless that it is 

 called "Crawling Mountain." For half 

 a century it alone had prevented a per- 

 manent roadway to conect the Inland 

 Empire with western Oregon. The en- 

 gineers conquered the slides by sinking 

 pillars through the loose super-rock anfl 

 anchoring to bedrock. On the pillars 

 they built a concrete viaduct just high 

 enough for the slides to thunder harm- 

 lessly underneath. 



The highest point above the river is 

 attained at Crown Point, a cliiT more 

 than seven hundred feet straight up al- 

 most from the Columbia. 



5Q 



