The Peter Grubb Hut is just off the Pacific Crest Trail (PCT), on the southwest side of a large meadow at the floor of Round Valley. You can see this expansive forest opening by looking northwest and down from the Castle Peak Trail. The hut is reached by hiking about one mile north from the Castle Pass trail intersection, where trails to Andesite Peak and Castle Peak branch off the PCT. The PCT section from Castle Pass to the hut starts out as a graded trail through forest and then descends toward Round Valley via switchbacks. You'll find the Peter Grubb Hut to your left—surrounded by trees. A short distance further north, the Sand Ridge Trail leaves the PCT westwards, while the latter leads north through mixed forest, providing access to Basin Peak, Paradise Valley, Paradise Lake, Warren Lake and Devils Oven Lake.
Unfortunately, the Peter Grubb Hut is in need of urgent repairs and the Sierra Club has decided to close the hut until these repairs can be made.
We apologize for this inconvenience but assure you that it is for everyone's safety. We look forward to making the repairs in a timely manner so the Peter Grubb Hut can be enjoyed again soon.
Clair Tappaan Lodge - 800-679-6775
When the Sierra Club hut reopens, you will find an upgraded, more robust cabin serving its previous function by accomodating a maximum of 15 overnighters in a sleeping loft on top of a main room with a wood-burning stove, tables, and a kitchen area [1,2].
References and more to explore
 Sierra Club: Lodges and Huts - Peter Grubb Hut [http://www.sierraclub.org/outings/lodges/huts/grubb.aspx].
 Sierra Club: Lodges and Huts - Summary Proposal for Expansion of Peter Grubb Hut to Reallocate Existing Space and Provide New Features to Improve the Visitor Experience [www.sierraclub.org/outings/lodges/huts/future/grubb_upgrade.aspx].