Christine,
In the 1840 Tithe Award and map (for Henshaw) Fogridge is shown – an 18 acre farm occupied by Jane Green and owned by Sir Thomas John Clavering, who also owned several other farms nearby. I think this is the Clavering family of Greencroft in County Durham. The tithe map only shows one house, no ‘High’ or ‘Low’. The 1841 census shows Jane Green aged 80, farmer, with a farm worker and a lead miner at Fogridge, again no high or low.
It is possible there may be references to the property in Clavering estate papers – you would have to search the National Archives catalogue to find out if they exist or are accessible.