For a map or complete description to all the trails order Porcupine Mountains Wilderness State Park: A Backcountry Guide for Hikers, Backpackers, Campers & Winter Visitors by Jim DuFresne from the eshop:
From the alpine ski area parking lot, cross M-107 to the winter trailhead on the north side of the road which marks an overgrown two-track. The Superior Loop heads south gently descending to Lake Superior and passing a junction with a crossover spur within a quarter mile and then the access trail to Union Bay Campground at Mile 0.4. It’s a quarter mile to the Union Bay West and East yurts.
A quick descent follows before the trail swings to the west near the Lake Superior shoreline and arrives at the White Birch Cabin at Mile 0.6. White Birch Cabin is a warming shelter in the winter but utilized as a rental cabin the rest of the year. This snug, 2-bunk cabin features a fire ring, picnic table and log bench outside. It’s not within view of the water but nearby a short spur leads to the rocky Lake Superior shoreline, the perfect place to catch a sunset.
Superior Loop heads south from the cabin and within a quarter mile reaches a posted junction with Deer Yard Trail. Head northwest (right) to continue on a two-track to reach the junction to Whitetail Cabin just beyond Mile 1. The eight-bunk cabin is a couple hundred yards down a spur trail and features a view of the lake through the trees and access to its shoreline that is made up of steeply tilted sandstone layers.
Return to the main trail and continue west to cross a smallish stream and then venture through a towering stand of hemlocks at Mile 1.5. Impressive trees to say the least. Deer Yard Trail switches from a two-track to more of a cobblestone pathway, passes through a few wet areas and just before Mile 2 curves to the south.
What follows is a sustained climb to M-107. You cross the paved road (watch for traffic!) and continue the climb on the other side reaching a junction with Big Hemlock Trail at Mile 2.7 To the west (right) Big Hemlock is closed to mountain bikes. To the east (right) it's a long and fun downhill run to the ski lodge reached at Mile 3.5.