Lesser Slave Lake is a lake located in central Alberta, Canada, northwest of Edmonton. It is the second largest lake entirely within Alberta boundaries (and the largest easily accessible by vehicle), covering 1,160 km² (450 sq mi) and measuring over 100 km (62 mi) long and 15 km (9.3 mi) at its widest point. Lesser Slave Lake averages 11.4 m (37 ft) in depth and is 20.5 m (67 ft) at its deepest.