Thornthwaite Crag stands in Wainwright's Far Eastern Fells, close to the largest fell in the area, High Street. It has an unusually high cairn at the summit, an area which provides an excellent panorama of the Lakeland fells to the west, with Bowfell being a particular highlight. To the east the Far Eastern Fells give way to the Eden Valley and then the Pennines in the distance. As Thornthwaite Crag stands at the head of a number of valleys, there are good views down these too, particularly Kentdale.
Thornthwaite Crag walks can be carried out directly from Hartsop via Pasture Beck, or by taking a path that partially follows the path of an old Roman road from Troutbeck. A method including Thornthwaite Crag on an itinerary that covers several Wainwrights on a Wainwright map in one day is the Kentmere Horseshoe. This begins in Kentmere village, heading for the first Wainwright fell on the route, Shipman Knotts. A ridge path then moves on to Kentmere Pike and Harter Fell, before the Nan Bield Pass leads to Mardale Ill Bell and High Street. Having reached the highest point of this Wainwright walk, Thornthwaite Crag is the neck Wainwright to tick off, before crossing the old Roman road to Froswick, Ill Bell and then Yoke, before the path winds down to the starting point again. This horseshoe walk is likely to take up much of the day but is a thrilling way to complete 9 Wainwrights in a day.
Further information about Thornthwaite Crag walks and the surrounding fells can be found in Book Two: The Far Eastern Fells, part of the Pictorial Guide to the Lakeland Fells.