Why not continue the logic of staying on good tracks and follow the track to the Guide Stone at 292279 and there turn left to cross the bridge over Glenderaterra Beck, still on a good track, turning off it at the bridge over Roughten Gill at 298276 where you can pick up trods up the south side of Roughten Gill to about 308278 from where you dead reckon to the ridge path half way between Gategill Fell top and the summit
see http://maps.live.com/?v=2&sp=Polylin...7nwy&encType=1