Summary 
| Difficulty | 5 Advanced |
| Length | 11.0 miles round trip |
| Starting Elevation |
8600 feet |
| Cumulative Elevation Change |
+2300, -2300 round trip |
| Navigation | Road and map |
| Time | Full day |
| Season | December through early May |
| Snowmobiles Use | Not permitted through mid-April. Moderate after mid-April to John Muir Wilderness boundary located south of Lake Mary roads. Always prohibited in John Muir Wilderness to Duck Pass. Contact Forest Service for transition date. [Please report illegal use of snowmobiles in this area.] |
| USGS Topo | 7.5' series, Crystal Crag, Bloody Mountain |
| Start | Lake Mary Road near Twin Lakes where the road is no longer plowed. The plowed parking area is just past (south of) the turn to Tamarack Lodge and Resort. |
Description
Duck Pass, located at the head of the Mammoth Creek drainage and on the Mammoth Crest, is a formidable objective for even the most advanced skiers. This tour, particularly two very steep sections, will test one's skiing and physical capabilities.
Reaching Duck Pass also rewards you with a magnificent view of the Duck Lake basin and the sheer granite peaks that form it. You can also see Silver Divide as you look down the Duck Lake drainage and across Cascade Valley.
Mileage Log
Numbers in parentheses
correspond to mileage points on map
Waypoint 1 to 2
Miles: 0.0 - 0.6
Elevation change: +150
From the trailhead (1), ski south on Lake Mary Road for 0.6 mile until you reach the turnoff (2) on the east (left) side of the road to the site of the mining town of Old Mammoth and present-day Old Mammoth.
Waypoint 2 to 3
Miles: 0.6 - 1.3
Elevation change: +300, -50
Continue south on Lake Mary Road for 0.7 mile until you reach the first turnoff to Lake Mary (3).
Waypoint 3 to 4
Miles: 1.3 - 1.9
Elevation change: +0
Turn south (left) off the Lake Mary Road and follow the road as it loops around Lake Mary for 0.6 mile until you cross Mammoth Creek and shortly thereafter reach a road junction (4). The road that continues straight continues around Lake Mary. The tour to Duck Pass turns southeast (left) onto the intersecting road.
Waypoint 4 to 5
Miles: 1.9 - 2.6
Elevation change: +150
Turn southeast (left) onto the intersecting road and ski through a campground, always staying right, for a total of 0.7 mile until you reach the end of the road and the Duck Pass trailhead (5). Although the trailhead sign may not be visible, locate it where the terrain begins to climb and where the top of a restroom is probably visible.
Waypoint 5 to 6
Miles: 2.6 - 4.0
Elevation change: +800
Enter the trees, ascend a gully, work your way onto the ridge located between the gully and Mammoth Creek, and once on the ridge continue to climb southeast along the ridge on more level terrain, passing Arrowhead Lake to the northeast (left) for a total of of 1.4 miles until you reach Skelton Lake (6).
Waypoint 6 to 7
Miles: 4.0 - 4.8
Elevation change: +250
Ski southeast past Skeleton Lake and then ascend parallel Mammoth Creek for a total of 0.8 mile until you reach the north end of Barney Lake (7).
Until you reach Barney Lake, there is no significant avalanche danger under normal conditions. However, at Barney Lake and beyond, all the steep slopes are very susceptible to avalanche. Do not continue to Duck Pass or ski under the steep slopes that surround the lake unless the snow is very stable.
Waypoint 7 to 8
Miles: 4.8 - 5.5
Elevation change: +600
Ski southeast along Barney Lake, after passing the lake turn south, and climb where the terrain dramatically steepens for a total of 0.7 mile to Duck Pass (8). In order to gain a much better vantage point, climb a short distance up the ridge to the west of the pass.
Return to trailhead
Miles: 5.5 - 11.0
Elevation change: +50, -2250
Retrace the route for 5.5 miles back to the trailhead (1).
