The SE ridge route has gotten a lot more popular than when this route page was created nine years ago. The path is well-trodden and easy to follow in most places. I only saw a couple of flags. There is a "Mountaineers" summit register container at the west summit.
As for the driving directions, the main place somebody might make a mistake is near Lost Lake. A short distance prior to Lost Lake, FR-5480 reaches a five-way intersection. DO NOT CONTINUE STRAIGHT. Instead, veer right to remain on FR-5480 and go around the East & North sides of the lake until reaching the desired Mirror Lake parking area(s). There is a "Trail 1302" sign (for Mirror Lake Trail) at the last left-bending road-turn just prior to its final uphill ascent to the trailhead. The trailhead, itself, is unmarked but obvious. Cars will need to park along the side of the road at the bottom of the hill, while high-clearance vehicles can find parking just beyond the trailhead.