Breich No. 1 and No. 2 Pits worked three main shale seams: the Barracks Shale, Broxburn Shale, and Dunnet Shale. The workings reached depths of 21 fathoms to the Broxburn seam, 63 fathoms to the Upper Dunnet, and 72 fathoms to the main Dunnet Shale. The shale was extracted via vertical shafts and initially transported overland to the Seafield Crude Oil Works, later redirected to Westwood following the 1930s reconstruction.

The site, located in the Breich mining area, still retains several original buildings, including the engine house and substation, which have since been repurposed for commercial use.

The Breich No. 1 and No. 2 shale pits were first developed around 1912 by the Pumpherston Oil Company Ltd., following their acquisition of mineral rights previously held by the now-defunct New Hermand Oil Company Ltd. These pits supplied shale to the nearby Seafield Crude Oil Works, located approximately one mile to the north. Notably, the operations at Breich were among the first in the industry to use electric power for winding and ventilation, with electricity supplied from Deans Crude Oil Works.

Production ceased in 1926 following the closure of the Seafield works. However, during the 1930s, the pits were modernised and reopened. Significant upgrades were introduced, including the use of mechanised shale cutters, shaking conveyors, and the construction of a new haulage system to serve the Westwood Crude Oil Works, located about a mile south. Often referred to as “Mid Breich,” the pits remained in operation until 1961, shortly before the wider closure of the Scottish shale oil industry.