Reached a depth of 450 feet at the Yorkley seam, which was only 2 inches thick at that level. Deeper down, at 700 feet, the Coleford High Delf seam measured a more substantial 7 feet in thickness. A secondary shaft, known as Hawkwell, served as the emergency or safety shaft. Today, the site is largely derelict. The mine office buildings remain but are in poor condition, and the spoil tip—though overgrown—still survives.

• 1935-1946 H. Crawshay & Co. Ltd
• 1947-1965 National Coal Board

Was the last to both open and close in the area, operating from 1935 until its closure in 1965. During the period of nationalisation (1947–1965), the mine produced a total of 2.4 million tons of coal, although it operated at a financial loss of approximately 50p per ton. After closure, efforts were made in 1994 to recover coal from the spoil tip by washing it, but this initiative was abandoned the following year. Local knowledge suggested the coal had largely been destroyed due to spontaneous combustion while the tip was still active, which had caused it to catch fire.