This trail starts at the Yellow Pine Trail
; it is necessary to pay close attention to the trail as it's quite easy to lose at times. The best guidance I can give is to look for the talus slope from the southwest side of Castle Peak and look for a ravine on the southern edge of that talus. You can also use the Trail Run Project mobile app
to help find your way.
The trail climbs up the southeast side of the ravine and is pretty easy to follow from there using cairns and ribbons tied in places along the trail. There is a pretty steep climb for the first quarter mile or so after leaving the Yellow Pine Trail
, but then it levels out into a nice flat track that skirts the edge of Castle Peak all the way to Castle Lake.