Elevation: 10,744 ft
Climbing and access information for this peak is on Page 256 of the book.
Err Peak is often climbed along with climbs of Pion Peak and Argosy Peak on the same day. I recommend climbing the peaks starting with Pion, then Err and finally Argosy. The round trip shown below covers 9.1 miles and 4,300 feet of elevation gain. USGS Trail Creek
Argosy Creek is accessed from ID-20 at Carey, Idaho. Look for the sign on the east end of town stating “Little Wood River Reservoir 11.0 miles.” See [(E)(1) on Page 261]. Take this good paved road out of town passing homes, farms and ranches. The road turns to good gravel before reaching the turn for the reservoir. Continue on the main road. At 17.4 miles, the road takes a sharp right turn and runs through the middle of a ranch. Continue through the ranch buildings for 6.8 miles to an unsigned junction just past a turn for another ranch.
This road, shown on the map below, is FS-126. Most maps show it as a 4WD road when, in fact, it is a good road suitable for most vehicles when dry. Follow FS-126 as it skirts around the ranch property and works its way into upper Muldoon Creek for 2.5 miles where the road is wide enough to park. This spot is just past the confluence of Muldoon Creek and Argosy Creek.
Muldoon Creek is clogged with willows. Finding your way across the creek and then through the willows may be the crux of the climb. The best spot we found was 0.1 miles south of our parking spot. Good luck.
Click on the links for John Platt and Dan Robbins to read their trip reports.