[4] This section of the A18 Snaefell Mountain Road from the Keppel Gate to the Windy Corner was built on sections of common grazing land that were transferred to the UK Crown following the sale of the Islands feudal and manorial rights by John Murray, 4th Duke of Atholl as Governor of the Isle of Man in the period 1824-1829.

[5] The Tynwald Disafforesting Commission of 1860 allowed for the proposed sale of mountain land held by the UK Crown to the HM Commissioners of Woods.

[14] The property a former Mountain Shepherd's cottage, owned by the Isle of Man Department of Agriculture, Fisheries and Forestry, was sold at public auction in 1994 and is now in private ownership.

[15] Contemporary photographs of the RAC Tourist Trophy races for automobiles held in the Isle of Man 1905–1922 and the Isle of Man TT races in the 1920s, show sheep-gates at Kate's Cottage[16] and also at Keppel Gate, with the name Keppel Gate in general referred to both locations.

[20] This included the Keppel Gate section[21] and Kate's Cottage[22][23] and the course later became known as the 37.73 mile Isle of Man TT Mountain Course for motor-cycle racing which has been used since 1911 for the Isle of Man TT and from 1923 for the Manx Grand Prix races.