These peaks are on private land, trails maintained by the Squam Lakes Association.
I just saw an online report (April 3, 2009) that the parking lot has been roped off and the trails posted as closed (presumably by the landowner and/or the SLA) due to "spring conditions". Not clear how long that will last or whether this is a regular yearly practice.
Parking lots are currently open (and snow-free for the moment). There are actually three lots: one for the Percival trail, one for the Morgan trail, and one (directly across from the Morgan trail) for the Rattlesnake hills (Bridle Trail I think was the trail name)
The Morse trail joins the Percival and Morgan trails very near their lower ends, so you can do the loop without any road walk.