In the mid-1920s, Pacific Coast Coal Company’s Mine No. 11 in Black Diamond was nearing the end of it economic life. With its impending closure, Pacific Coast Coal undertook development of a new underground coal mine beneath Cedar Mountain, about half-way between Maple Valley and Renton. To access the coal, Pacific Coast constructed a mile-long tunnel under Cedar Mountain from the Renton-Maple Valley highway near the Cedar River towards Lake Desire. This 1925 photo shows what was called the rear entrance to the mine and comes courtesy of the Renton History Museum. This “rear entrance” would have been located just south of a site on SR 169.

Photo provided by Bill Kombol