The Howgill Fells are uplands in Northern England between the Lake District and the Yorkshire Dales, lying roughly within a triangle formed by the town of Sedbergh and the villages of Ravenstonedale and Tebay. The name Howgill derives from the Old Norse word haugr meaning a hill or barrow, plus gil meaning a narrow valley. Geography The Howgill Fells are bounded by the River Lune (and the M6 motorway to the west), to the north by upper reaches of the River Lune, and to the east by the River Rawthey. The fells include two Marilyns: The Calf – and Yarlside – and a number of smaller peaks, including five Hewitts. Since 2017, the entire range has been included within the Yorkshire Dales National Park. They have been within the modern county of Cumbria since the county boundary changes in 1974. They were originally shared by the West Riding of Yorkshire and Westmorland. Geology Unlike the Carboniferous Limestone landscapes typical of much of the Yorkshire Dales and Orton Fells, the range is formed from lower Palaeozoic slates and gritstones. An inlier of Ashgill age rocks of the Ordovician Dent Group in the vicinity of Backside Beck in the east are the oldest rocks in the range whilst the oldest Silurian rocks are the laminated siltstones of the Llandovery age Stockdale Group. These are overlain by more than 250m thickness of dark grey mudstones and siltstones of the Brathay Formation which, with the overlying Coldwell and Wray Castle formations are collected together as the Tranearth Group and, in age terms, span the Wenlock / Ludlow boundary. The larger part of the range is formed from sandstones of the Coniston Group. This unit is roughly 1000m thick; it includes a basal Screes Gill Formation up to 300m thick and also contains numerous siltstone bands. These are overlain by the sandstones, mudstones and siltstones of the Bannisdale and Kirkby Moor formations, collected together as the Kendal Group. Structurally the bedrock is folded on a broad scale into a roughly east–west aligned Carlingill Anticline with the Castle Knotts Syncline to its south. Numerous smaller amplitude folds are developed on the limbs of these two folds. A series of normal faults aligned between N-S and NE-SW cut the range whilst its eastern and southeastern margin is defined by a combination of the Sedbergh, Rawthey and Dent faults. Quaternary deposits include widespread glacial till in the valleys