With the future of the Chinese Diggings site in question I figured it to be a good time to check out this interesting piece of history. 
The Diggings are a series of maze like trenches resulting from ground sluice mining operations. This is one of many entry points into the trench system which can become quite deep at some points.
The mining operations were believed to have been active during the 1890’s and early 1900. Since the entire area is essentially ancient river bed, one can see river cobble far below ground.
Although called Chinese Diggings, there is no record of who actually did the digging. The environment in the depths of the trench is markedly different from the surface. Cool and damp it sustains different types of plant life than the Oak trees and abundant Poison Oak found above.
Intersecting trenches covered in moss

In some spots, the trench reaches depths of 20 to 30 feet.
Artifacts!
The way out
The Chinese Diggings is flanked by Hwy 50.