I did the exact same hike a few years back and found a spot to pitch the tent right near the junction of the Lincoln Brook Trail and the Owl's Head Path. It might not be totally legal as it was just off the trail and next to the brook, but if you "Leave No Trace" I don't see it as a problem. This is of course, if you can find the Owl's Head Path. The cairns and blazes have been removed. Do a search on this site for Owl's Head threads to learn more.
KD Talbot
Well its been about 8 years and the site is still there... There are other (illegal sites) 100 feet or more to the north, but the fire rings have been scattered.
Not so here....room for two tents on well packed earth, free of stones, steps to the brook, actually better maintained than state park campsites, and with a thoughtfully placed supply of fallen birch and a long limb for hanging bear bags; .
The fire ring has not sunken into the earth, so I assume the rangers come out and dismantle it. I didn't try to measure the 200 feet, but this one is the furthest off the trail. There are signs of waste, but deep among a lattice of fallen trees
North of this site and the Owl's head path, some people crossed west of the brook. I just saw the equipment--can't attest to conditions over there.
Owl's head path has two cairns (for redundancy?), one topped with a pink bracelet. I met two parties coming from the north who very concerned about finding the path.
And yes the rangers were out Saturday night, returning from somewhere north of the suspension bridge. They wear green flashing led's at night.