The approach starts at the Glacier Canyon Trailhead at the south end of the Tioga Lake Overlook (just outside of YNP on CA SR-120). Sleeping in your car here is allowed. Benefits include: it's free, rangers won't bother you, and as of the summer of 2001 bears were not making visits to this area. You may also be able to sleep down by the lake.
Opinion from John: This route provides a much more scenic and nicer start than the standard West Slope route from the YNP Tioga Pass Entrance Station. I would go as far as to recommend this route over the standard one in every case except for where the trailhead is important (e.g. if you are doing a Mount Dana to Mount Gibbs traverse).
This route follows the Glacier Canyon Trail which is also used to reach the Dana Couloir. Head around the south end of Tioga Lake, crossing a small creek (1.5 foot wide?), and follow the shoreline north. It's easy to lose the trail once you make start heading north so just go cross-country until you run into a larger creek in the woods. Check the TopoZone map to get a rough idea where this creek is. At this point you should find the trail again heading up the creek drainage going east. Follow this well-defined trail up to Glacier Canyon.
Once you reach the upper meadows, look south for the class 2 hiking route. This will take you to the bottom of the Northwest Ridge from where it's very straight-forward to reach the summit. Either hike along the ridge or across the West Slope to join the main use trail. After the snow has melted, it's easier to hike cross-country and join the standard use trail ascending the West Slope. The overall length of this route is about the same as starting from the YNP Tioga Pass Entrance Station.
None late in the season when the snow has melted. Earlier in the season crampons and an ice axe are useful for snow travel.
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