NEHL - The Mary & Air Pit was one of the later workings opened by Beamish Colliery, first being sank to connect with the other Beamish Pits in 1849. It likely utilised an even earlier working - the Ice Pit, which was just east and had its own wooden waggonway long disused by the 1850s. The Air Pit connected to the Beamish/Stanley Waggonway on an existing trackbed which originally led to Kip Hill on an older working which had disappeared by the 1850s. By 1857 it featured a pit pond, two waste heaps and 5 sidings around one central building.

It grew exponentially by the 1890s, with a long line of coke ovens on its western side and a larger pit reservoir to the south. Given part of the Mary Pit was mined for gas coal, it featured a gasometer on site. East Stanley was certainly ay least partly built to house workers of the Mary Pit, and there was a path which directly led to the pit through the View Plantation which still exists.

750 men and boys received 14 days notice in September 1935, however it appears the pit trundled on until the 1960s. This is confirmed in the Newcastle Journal, stating the 480 miners left were "quietly accepting" of the closure on March 25th. Around 180 of them found jobs at nearby collieries while the remainder were onboarded at Dawdon and Monkwearmouth, with the NCB putting on buses.