Access: The Alpental Valley is located at - catch this - the Alpental ski area. Most tours are accessed from traversing out the upper gate of the resort, or from the furtherest lot. Its a very popular spot.
Alpental provides access to many excellent ski options and some truly rowdy terrain. The ski area itself has some of the more technical and steep lift accessed skiing in the state. Most of this is through the backcountry gates and everything in the zone from the resort to Pineapple basin is easily accessible with traversing and side stepping. Snowboard access isn't adviced as the high traverse requires much side stepping. There are lots of cliffs and steep drops, so be cautious and don't always rely on following tracks. If skinning staight from the lot, the track heads out a groomed path from the the back lot and then follows a traversing line on the left treed slopes. Towards the end you will reach source lake that is often the site of dramatic avy dabris. From the Lake you can ascend towards pineapple basin and ski the basin, or head up to ski slopes on Bryant or the Bryant Coulior. If you head straight from Source lake up towards Chair Peak you have other great options from this bowl and down towards Snow lake; a common way to start the chair peak circumnavigation. Or you can wander up and right to Snow lake and ski slopes around this zone or out towards Rock Thunder.
On the other side is Mt. Snoqualmie: See the Mt. Snoqualmie Section for more info