We parked in the Trough House Bridge Car park, which is free but accepts donations. We wandered slowly along the valley, following the river before arriving at Low Birker.
From here we started the ascent. Following the path up to Low Birker Tarn, then through the marshes toward Green Crag.
We climbed the last bit up to Green Crag where we stopped and had lunch enjoying the views over Harter Fell and Hardknott. Not a spot of wind, and really warm...
Until about half an hour later when the cloud rolled in. We couldn't see more than 10 metres in front of us, so beat a hasty retreat back the way we came. The fog stayed with us the whole way, it was just as thick on the valley floor!
One more bagged!
At least you got that nice hike in and some really nice photos before the fog descended 
