The Crovan's Gate Mining Company, also known as the C.G. Slate Company, is the company that mines slate, and formerly copper, from the hills around the Skarloey Railway.
The Company existed by 1806 and owned a copper mine in the foothills of Ward Fell. They built a horse-drawn plate way to transport the ore from Cros-ny-Cuirn to Balladwail for shipment. They relaid this line in 1820 with ”fish-belly” edge rail, and extended it up the Benglas valley to the mine.
In the 1860s, they upgraded the line for steam haulage. The Company originally intended for the railway to continue as a mineral line only, but the re-discovery of the ancient sanctuary of Skarloey meant the Board’s thinking underwent a change. They invested heavily in turning the sanctuary into a spa. The expected passenger traffic, however, never materialised.
The Company's copper mine was profitable, but by 1900 there were signs too that the veins of copper were beginning to run out; but miners searching for further copper in the foothills came upon good slate. The Company’s main interest was in copper, but they had no objection to using slate as a secondary freight. They lost interest, however, when the copper ran out at last, and proposed to close down. The Company was bought out by Sir Handel Brown in 1909, with the railway included in the deal.
The copper mine was swiftly closed down, while the slate quarry remained profitable until 1924, though the quarry remained in operation until 1960, when it was sold to the Ministry of Defence.
The Company had an office at Crovan's Gate, near the exchange sidings. By 1958, the building's sign read "C.G. Slate Company", suggesting the Company had been renamed. The office was still around in 1984.