30 
CONCLUSION OF THE OFFICIAL REVIEW, ETC. 
the Columbia river, the route being favorable and the grades light. The total distance from 
Benicia to Fort Vancouver by this route is 760 miles. 
Lieutenant Abbot, corps of Topographical Engineers, examined the Des Chutes valley to the 
Columbia river. The impracticability of constructing a railroad across or along the deep canons 
cut in the plateau by that river and its western tributaries was fully demonstrated. Pro¬ 
ceeding to Vancouver, the Cascade mountains were crossed a short distance south of Mount 
Hood, through a pass discovered by the party, which is practicable for a railroad, though 
probably inaccessible on the eastern side. Through this pass an ascending grade of 100 feet 
per mile would be required for 14 miles, and a descending grade of 123 feet per mile for 30 
miles. The summit is 4,500 feet above the sea. For about 55 miles the construction would he 
difficult and expensive. The pass is a good one for a wagon road. 
Lieutenant Williamson was compelled by the lateness of the season to return by water to San 
Francisco to prepare for a second survey in the Sierra Nevada, near the head of Carson river. 
Orders were left for Lieutenant Abbot to survey the route to Fort Reading lying between the 
Cascade and Coast ranges. After Lieutenant Williamson’s departure, hostilities were com¬ 
menced by the Indian tribes on this route, which rendered an escort for the small topographical 
party absolutely necessary. The exigencies of the public service in that region were such, how¬ 
ever, as, in the opinion of the commanding officer at Fort Vancouver, to require him to attach 
the escort that had accompanied the party from California to his command, and it was therefore 
necessary either to abandon the duty or pass without an escort through a hostile Indian country. 
The latter course was adopted, and, although the absence of the escort rendered it impossible to 
make side explorations, the result of the survey proved the route to he more favorable than was 
anticipated. With the means to make side explorations, it is thought that a route might have 
been found through this fertile and settled country better adapted to a railroad than the line 
traversing the sterile region east of the Cascade range. 
Through the Calapooya mountains, -which separate the Willamette from the Umpqua valley, 
an excellent pass was found ; giving, without difficult or expensive construction, an ascending 
grade of 31 feet per mile for 2 miles, and a descending grade of 66 feet per mile for 5 miles. 
The summit is 900 feet above the sea. In the Umpqua valley there are a few hills where the 
work would he difficult, hut it is thought that these may he avoided and a good location obtained 
to the Umpqua canon. This pass, a serious obstacle to the construction of a railroad, leads 
through the Umpqua mountains to Rogue river valley. Its summit is 2,000 feet above the sea. 
An ascending grade would he required of 207 feet per mile for 7 miles, with some heavy rock 
cutting, and a descending grade of 192 feet per mile for 2 miles. By side location the latter 
might he greatly reduced. It is possible that an examination of Cow creek canon might have 
developed a more favorable route. 
In Rogue river valley the Grave creek hills present the principal obstacle. By following 
Wolf creek to Rogue river they might probably he turned, hut this examination could not be 
made. There is a pass from the valley to the great plateau east of the mountains, which, if as 
favorable as reported, would make a good connexion with the route surveyed by Lieutenant 
Williamson. 
Through the Siskiyou mountains, which separate Rogue river and Shasta valleys, the con¬ 
struction of a railroad would be very difficult. The summit of the pass surveyed is 4,500 feet 
above the sea. An ascending grade of 130 feet per mile for ten miles, with a tunnel six miles 
