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).
Hills in the Puget Lowland as Lake Washington; and numerous kettle lakes, and Puget Sound itself. High points on the plateau remain, most of which are a drumlin (rocky glacial debris), or a bedrock intrusion that predated glaciation. Hills above 500 feet are considered exceptional. Hills are glacial deposits unless otherwise noted. King, Pierce and Snohomish Counties run up to the crest of the Cascades where their high points reside; therefore, the Cascades and attached foothills are excluded. Likewise for Thurston County in the Mount Rainier area, and Mason County's Olympic Mountains foothills. Landforms north of the Tacoma Narrows (Island, King, Kitsap, Pierce and Snohomish