Note: It is not recommended to approach McGillicudys Peak from the Lake Cavanaugh area. The bridge across Deer Creek (as shown on USGS and Green Trail maps) has been removed.
Follow SR530 east to Oso. At 0.8 miles past the Oso store, turn left onto Brooks Creek Road. After 0.5 miles, Brooks Creek Road will split - take the left fork, which at this point will turn to gravel. It will look like a driveway at first (you will pass two homes) - continue 0.3 miles until reaching a DNR gate. Park in the wide area just east of the gate, or in the switch back just downhill. Do not block this gate, as it gets used on a regular basis, particularly on weekdays. If you decide to drive in while the gate is open, you do so at your own risk.
Note: As you start up this road, you will notice a few 'stay out/danger/slide' signs. These are leftover from the March 22 slide, and have not been taken down. The route to McGillicuddys Peak will get nowhere near the Skaglund Hill slide area. The DNR employee I saw today (5-22-14) had no problem with me being in this area.
McGillicuddys Peak route map. The dashed black line from Myrtle Lake shows a likely hiking route from Mount Higgins, provided one could get access to the trailhead.
Start up the mainline, ignoring spurs. At just under four miles, a prominent spur will lead off to the right. Ignore this spur, and continue straight ahead for another three-quarters of a mile, where the mainline will switchback to the right. There is a possible route variation here if you continue straight ahead (not shown on USGS map), which I will leave to you and Google Earth to figure out. This variation would probably be best if you intended to visit the Granite Lakes area as part of your trip. Before continuing up the mainline, take a moment to enjoy the view to the west.
At about the 8.4 mile point on the mainline, you will approach another gate. This is at the point where you cross over from DNR land to private timber land. The signage here was a little confusing: one sign said 'No Trespassing', and the other sign had rules posted for recreational users. I figured the recreational use sign would not be there if walk in use was not permitted, so I continued on (I'm assuming the 'No Trespassing' may apply to motor vehicles). A short distance past this gate, and just before crossing a 3300' saddle, you will notice a short spur leading off to the right. Take a moment to turn off here, as this spot will provide the best west views on your journey.
West view on the way up McGillicuddys Peak. This point would almost be a worthy destination in its own right during the winter months, as the views are quite expansive (east through northwest)
Cross over the saddle on the mainline, ignoring the prominent left fork at the saddle. The mainline will descend a couple hundred feet over the next mile. At about the 10 mile point, you will arrive at 'Maggie's Meadow'.
Maggie's Meadow on the way up McGillicuddys Peak
At roughly one-quarter of a mile past Maggie's Meadow, turn right onto the spur that will lead you to the summit of McGillicuddys Peak. I was able to ride this spur to 3400', where further bike progress was halted by snow. Please note that in most years, you would not be able to ride to this point until June (2014 was a low-snow year). Even when this road is completely melted out, at some point you will want to begin walking, as the road bed deteriorates somewhat near the top. The summit spur will get you within a few hundred feet of the summit, after which point, simple scrambling will put you on top. There are no 360-degree views on McGillicuddys Peak, but by moving around the summit area a bit, you will be able to get views in all directions except west. Total distance to the summit via this route is about 11.8 miles.
McGillicuddys Peak north through east pano. Granite Lake can be seen at the bottom of photo.
For the last several miles of this route, you will be on private timber land, and the standard rules apply: no camping, no fires, no dumping, etc. I saw no requirement for a Discovery Pass at the DNR gate. Yield to any trucks you may encounter on these roads.
When to Climb
Riding in this area would probably be best from June to November most years.
Camping is not allowed on the private timber land in this area. If you were determined to camp near McGillicuddys Peak, there is some DNR land surrounding some of the Granite Lakes Potholes (numerous small lakes north of Granite Lake). I will leave it to you and your mapping software to figure this out.
Here is a photo for those who would prefer to hike in from Mount Higgins. Hopefully the C Post Road will reopen someday, allowing access to the trailhead. As can be seen in the photo, it appears most of the hike from Myrtle Lake would be in old growth timber.
McGillicuddys Peak and Myrtle Lake from Mount Higgins