Established in 1855 by the Parkside Mining Company, this mine quickly became a prosperous venture, boasting significant output such as over 100,000 tonnes of ore raised in 1873 from a vast flat deposit in the First limestone layer. However, by the mid-1870s, production began to decline rapidly. When the royalty was renewed in 1875, the property to the east of the road was divided between the Goosegreen Co. and the New Parkside Co.

In 1877, the company expanded operations by accessing ore in the Fourth limestone layer, sinking a new shaft (No.19). In 1894, they acquired the Crossgill mine, which had been extracting ore from the same shallow body, along with the Dalmellington No.7 pit. By 1913, Crossgill mine stood as the sole remaining operation, with all others closed by 1925.

The Parkside Company managed multiple mines in West Cumbria and numbered their pits chronologically, without specific reference to individual mines. Therefore, Pit No.19, situated at Parkside, does not imply that there were necessarily 19 pits at that location. For instance, Pits Nos.11 & 14 were located at Salter, and Pit No.20 was at the Winder mines in the Windergill valley.

Noteworthy finds from this mine include exceptional baryte specimens, featuring crystals ranging from a clear pale yellow to a rich chocolate brown, often elongated and slender on a distinctive open dolomite matrix. Additionally, calcite crystals, dolomite, hematite, and quartz were reported, along with pseudomorphs of hematite after scalenohedral calcite.