Overview
If you have taken the time to hike up to Castle Peak, it is well worth the effort to scramble as far as you want to go along the NW connecting ridge between Castle and USGS Peak.
The ridge never gets harder than class 3 scrambling, but the views are spectacular and the closer you get to the ridge the more you can feel the exposure into the north bowl of USGS peak.
Getting There
Follow the directions to Castle Peak and then head south along the only ridgeline connecting Castle Peak and USGS Peak.
Route Description
Scramble along the ridgeline as far as you feel comfortable. The closer you get to USGS Peak, the steeper the terrain becomes. When you feel you have met your limits, turn around and return the way you came, or drop down a number of steep drainages back into Upper Cedar Creek (bushwhacking may be inevitable in the bottoms of any drainage--have fun exploring!!)
The rock on the ridge always remains a beautiful consistency of rotten, chossy Lost River range limestone crap.
Essential Gear
1 ice axe, crampons (if early season and you are unsure of yourself on short steep snow sections), camera
Geology
Keep your eyes open and you will see first hand why limestone was once a sea floor.
There are 2 very prominent bands of fossils on this ridge.
The first is mostly clam shells at about 10,200 feet and the second band is plants and what looks like tube worms (my fossil identification is lousy) at about 11,000 ft.