Cuillin range. Cracks and fissures in the rock provided pathways for later magma intrusions, leading to dykes of basalt which are commonly seen across Skye. The Red Cuillin also have volcanic origins, being formed from a later intrusion of acidic, granitic rock. This granite was more uniformly eroded by wind and water than the gabbro and basalt, causing the red hills to have smoother outlines. The Cuillin provide classic examples of glacial topography and were the subject of an early published account by James Forbes in 1846 (who had become a fellow of the Royal Society of Edinburgh aged only nineteen).
Cuillin proportion compared to other equivalent land sales. Following the death of John MacLeod in 2007 his successor, Hugh Magnus MacLeod of MacLeod, found alternative funding sources, and as of 2017 ownership of the main range remains in the MacLeod family. The "Strathaird, Torrin and Sconser Estate" lies on the eastern side of Glen Sligachan, encompassing the Red Cuillin and Bla Bheinn: it is owned by the John Muir Trust, a charity that seeks to protect and enhance wild places. Strathaird Estate was formerly owned by musician Ian Anderson, the frontman for Jethro Tull, who sold the estate to the trust