Walking in the United Kingdom the scrambling suddenly becomes much more serious. In Britain, the term "mountaineering" tends to be reserved for technical climbing on mountains, or for serious domestic hillwalking, especially in winter, with additional equipment such as ice axe and crampons, or for routes requiring rock-climbing skills and a rope, such as the traverse of the Cuillin ridge, on the Scottish island of Skye. The British Mountaineering Council provides more information on this topic. Navigation and map-reading are essential hillwalking skills on high ground and mountains, due to the variability of British and Irish weather and the risk of rain, low cloud, fog
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