Lake Tahoe's winter wonderland offers perfect powder, groomed snow covers the slopes from November through to April. The snow can be enjoyed at any of 15 alpine and 13 cross-country ski areas, encompassing world-renowned ski resorts. At South Lake the best known are Sierra, Kirkwood and Heavenly, all offering steep, deep and scenic runs; on the North Shore is Squaw Valley and Alpine Meadows. The total ski terrain of more than 17,500 acres offers hundreds of runs catering for all levels of skiers and boarders, from powder in the trees, moguls and open bowls to perfect corduroy cruisers. Some of the area's more famous runs provide adrenalin-pumping challenges for advanced skiers. All the resorts offer ski instruction and child-care facilities.