Worked the Milwr Vein, which ran east to west, passing north of Brynford Hall. The main working area appears to have been west of the Hall, where a significant waste area remains. Mining activity in the area has left a legacy of earthworks and subsidence, particularly visible on both sides of Brynford Road as it ascends from the former workhouse, now Lluesty Hospital.

Further evidence of mining extends to the fields south of Brynford Hall and west of the modern Pystyll housing estate, where shafts following the east-west trend of the Ellis and Beili-gwyn Veins can still be traced. A day-level was constructed beneath the Halkyn-Holywell Road for drainage, and water continues to flow from a discharge point at SJ 1923 7470, marking the lasting impact of historical mining operations in the area.

The Brynford Hall Mining Company operated until 1870, when the mine was absorbed into the Milwr Group and later became part of the Herward Mines.