The Rocky Mountain Trench, also known as The Valley of a Thousand Peaks or simply the Trench, is a large valley in the northern part of the Rocky Mountains. It is both visually and cartographically a striking physiographic feature extending approximately from Flathead Lake, Montana, to the Liard River, just south of the British Columbia-Yukon border near Watson Lake, Yukon. The trench bottom is 3-to-16 km (2–10 miles) wide and ranges from 600–to-900 metres (2,000–3,000 feet) above sea level. The general orientation of the Trench is an almost uniform 150/330 degree geographic north vector which has also become convenient for north/south aviators.