[How do I find benchmarks on old USGS Topo map?]

I found this one I believe is described by the post by DaveD. I am not convinced it is the same one I have been looking for shown in the 1915 topo map as BM 2707..

Google Maps location is 35.570865,-117.8400142.

[How do I find benchmarks on old USGS Topo map?]

That looks like great information. I am going to try this one again. I was on the ARCGIS website where it overlays the older map onto today's contours and they look much different. Also, the road on the old map is heading parallel to, but significantly north of the existing road.

 

Yesterday, I was looking for a benchmark (BM 1965) at the road junction named "Salt Wells" on the same map. I found an old rusted 2-3" steel pipe laying on the ground. Could that have been it, but someone dug it up out of the ground?

 

Strangely, I have randomly found many markers out in the desert, but I have not found those on any map and the ones on the maps I can never find out in the desert.

[How do I find benchmarks on old USGS Topo map?]

I have been looking for several benchmarks on a 1915 USGS topo map. For example, on the Searles Lake, CA map it indicates BM 2707 with an "X" near a dirt road. My question is, how accurate is the elevation? Can I look along the 2700 elevation line on a modern topo map and expect to find the benchmark nearby? Any other tips on how to find it?