Strathmore (Gaelic: An Srath Mòr) is a strath in east central Scotland running from northeast to southwest between the Grampian mountains and the Sidlaws. It is approximately 50 miles (90 km) long and 10 miles (16 km) wide. Strathmore is underlain by Old Red Sandstone but this is largely obscured by glacial till, sands and gravels deposited during the ice age. Its northeast to southwest alignment is influenced by the underlying geological structure of the area which reflects the dominant Caledonian trend of both the central lowlands and the Highlands of Scotland; its northern margin reflects the presence of the Highland Boundary Fault.