Below is yet another map, this one an 1885 USGS map, which shows the same layout as the ones above. An interesting feature of this map is that it shows the creeks crossing the road (and they mostly jive with the creeks in the 1873 map above). Notice that the northern-most point of the road is where it crosses the main artery of Summit Creek, probably where it was easiest to cross. A short distance southwest of that northern point, both creek maps also show the course of an arterial creek crossing the road. But that is not the the current course of that creek--sometime in the past, the creek has diverted itself onto the old road for a few hundred feet and then it connects up with Summit Creek. The creek needs to be re-diverted to its natural course, and off of the road. The 1879 survey shows a small bridge at the point where the creek used to cross the road; the 1915 survey shows a culvert at that same point.
After the creek dries up in the summer, you can walk on the actual road again. See photo below this map.
Apparently, this is a common occurrence--creeks using the road as an easier path--after a strong storm or extra snow runoff. Any spot where the creek crosses a road, and the road is only dirt, the water can take the path of least resistance. After a few years, the road becomes the creek, unless barriers are placed to stop it.
In the December 2005 rain storm, this occurred on the old road in a different spot--the water flowed for a few hundred feet on the road.
Below is the section of the old road described above after the water dries up in the summer.
In the spring, this is a flowing creek.
It is clearly the road: it is exactly where both old road surveys place it, and it is perfectly straight, unlike a natural creek.
Below is the computerized plotting of the 1915 California State Survey of the old highway and the 1879 County Survey along with the GPS-surveyed current visible trail.
Hidden for 95 years--
Four years after I located the survey, I've now located the long-lost hand-drawn plotting of the 1915 survey:
Below is a portion of the old state highway drawn just 2 months after the 1915 survey was made (this map faces south, rather than the usual north). The station numbers match up exactly with the survey (you can see the numbers in the survey page above from 480 to 485), and the surveyor's notes match up. This set of maps for the entire 1915 survey from Lake Tahoe to Auburn consists of 31 sheets, each 32" x 42".
These maps were drawn by E. Goodwin, while the survey was made by A.J. Beakey. Goodwin must have made his own visit to the road, making new notes that were not in the survey. One interesting note is his label of the northern road as "Winter Road" which the surveyor had labeled as "Old Abandoned Road." This is what I had suspected for years--the older and steeper northern road continued to be used when snow kept the better main road closed.
The map also shows that the "Emigrant Gap (to Donner Lake) Road" ended at the creek going into the lake, as did the road to the east of the creek--the "McKinneys to Donner Lake Road." Who knew that the state considered that creek the dividing point between two highways? It's now the bridge next to the gift shop.
This map also pinpoints the "Old Saw Mill" and the bridges and culverts that were noted in the survey.
Below is a portion of the first AAA map of this road, drawn in May 1916, just 8 months after the state survey of the old road, and 10 years before new Highway 40 opened.