REPORT OP CAPTAIN HUMPHREYS TO THE SECRETARY OF WAR, 1856. 
29 
Either standard applied to the two routes—the route to San Diego by Warner’s pass, and 
that to San Pedro by the San Gorgonio pass—will give about the same total cost for each. If 
the object is to reach the bay of San Francisco, the route through the San G-orgonio pass is 
preferable, since, after reaching San Diego through Warner’s pass, at a cost equal to that of 
the route through the San Gorgonio pass to San Pedro, there would remain the distance between 
San Diego and San Pedro—nearly 100 miles—over which it would be necessary to build the 
road. 
In obedience to instructions from the War Department, dated May 1, 1855, a party was 
organized by Lieutenant R. S. Williamson, corps of Topographical Engineers, to examine the 
country lying between the Sacramento and Columbia rivers, with a view to ascertain the pra cti- 
cability of connecting their valleys by a railroad. 
The first 200 miles of the route—from Benicia to Fort Reading, in the Sacramento valley— 
pass through a settled country. The average grade would not exceed five feet, and bridges 
would form the only expensive item in the construction of a railroad. Timber and water are 
abundant. 
From Fort Reading, two routes to the Columbia river were examined—-one east of the Cascade 
range, and the other between it and the Coast range. The former crosses the western branch 
of the Sierra Nevada by Noble’s pass—a difficult location for a railroad, as there is an ascent, 
in a distance of 40 miles, of about 6,000 feet. A better line for crossing this range can be had 
by ascending Pit river along the route surveyed by Lieutenant Beckwith. A careful examina¬ 
tion of the two canons of this river developed results less favorable than those obtained by 
Lieutenant Beckwith, but nevertheless demonstrated the practicability of constructing a rail¬ 
road near them. 
The route beyond the upper canon of this river lies for about 250 miles over a plateau— 
mostly sterile, though well supplied with water—-elevated between 4,000 and 5,000 feet above 
the sea. This plateau extends from the western chain of-the Sierra Nevada, northward, beyond 
the Columbia, gradually declining towards that river from the head of the Des Chutes valley. 
Where timber is wanting in the immediate vicinity of the route, which rarely occurs, the 
mountains bordering it on the west will furnish an abundant supply. 
For nearly the whole distance the average grade will be less than 25 feet, though in a few 
instances it rises to 100 feet, per mile. Difficult work will be found near Upper Klamath lake, 
and between it and Klamath marsh, where some heavy cutting and filling will be requisite. 
At the latter place it will be necessary to follow the canon of Klamath river for about six miles. 
Near the head of the Des Chutes valley the party divided. Lieutenant Williamson, after a 
careful examination of the Cascade range in this vicinity, crossed it near Diamond Peak by a 
pass through which a wagon road has been made. Both the ascending and descending grades 
were found to be very abrupt. By the road, the ascending grades were for 2.5 miles 231 feet; 
for 4.7 miles 72 feet, and for 2 miles 42 feet per mile. The descending grades were for 5 miles 
23 feet; for 3.7 miles 512 feet, and for 2.5 miles 311 feet per mile. Below this point they were 
all less than 125 feet per mile, and they continued to diminish rapidly. The above grades 
might be reduced by a side location to an ascending grade of 150 feet per mile for 7 miles, and 
a descending grade of 180 feet per mile for 16 miles, and perhaps even still further. There 
will be great difficulty in cutting through the dense forest. The summit of the pass is 5,600 
feet above the sea. 
After crossing the Cascade mountains, the Willamette valley was followed for 150 miles to 
