[1] The large stream (average flow 100 litres/second) has been shown by dye testing to resurge at Black Keld, some 4.4 kilometres (2.7 mi) to the WNW 225 metres (738 ft) lower.

[2] Eli Simpson, a founder of the British Speleological Association, had become convinced there was a large undiscovered cave system in the area and devoted much of his time to finding it.

member Bob Leakey, who recruited a team of female co-workers from Yeadon aircraft factory to help the exploration of Mossdale Scar.

[3] It is a very challenging cave system prone to flooding, with many passages involving long wet crawls while other sections can be neck-deep in water; many of Leakey's explorations were conducted solo as few contemporaries had the necessary endurance.

Realising immediately that the six cavers who remained inside the cave system were in danger, she ran 4 kilometres (2.5 mi) across the moor to raise the alarm.

The cave rescue teams found the bodies of five of the cavers in the Far Marathon Crawls, and Bob Leakey led a search party to a location where he believed the sixth might have survived, without success.