Little Eggleshope, Wiregil and California, are mentioned in this memoir on P 148.
Dunham will also give NGR's for the levels, but as previously, mentioned you MUST be extremely watchful on Raby Estate's land.
At one time, before the right to roam act, they would give you written permission to walk the surface, but as I understand it this is now seldom granted.
However, most of their land does have maps posted showing where public footpaths are located.