Elevation: 10,700 ft
Prominence: 400
Climbing and access information for this peak is on Page 256 of the book. Livingston Douglas added a new route and new photos. As of this update, peakbagger.com has this peak and Err Peak mixed up. I requested a change. Livingston Douglas provided a trip report of a 4-peak ridge traverse found at the following link: The Argosy Adventure. Updated October 2025
Pion Peak is often climbed along with Err Peak and Argosy Peak on the same day. The round trip shown below covers 9.1 miles with 4,300 feet of elevation gain. USGS Trail Creek
A Google Earth image of the Argosy Trio
Ascending the northwest ridge of Pion Peak
Access
Argosy Creek is accessed from ID-20 at Carey, Idaho. Look for the sign on the east end of town stating “Little Wood 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.
FS-126 access
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.
My GPS track for the Argosy Trio. Matt Durrant, Mike Fox and I hiked the loop portion clockwise. We skipped Peak 10500, but it can easily be climbed from the head of Argosy Creek.
Elevation profile. The great thing about combining all three peaks in one day is that once you make the first peak, the up and down to the other peaks is minimal.
Use the links below to read trip reports from John Platt and Dan Robbins covering their 3-peak excursions.
Pion Peak. Dan Robbins Photo
Pion Peak as viewed from Argosy Peak. George Reinier Photo
The Entire Northwest Ridge by Livingston Douglas
The triad of Pion Peak (hump at far left), Err Peak (just right of Pion Peak in the distance), and Argosy Peak (well right of center) as viewed from Peak 10500 to the northwest on a smoke-hazy morning. Livingston Douglas Photo
Northwest Ridge FULL, Class 2
The Climb
From the 9,900-foot connecting saddle with Peak 10500,scramble up short scrub and scree/gravel with some goat trails to help. Climb up over a gentle ridge hump that looks much more intimidating from the saddle than it turns out to be. Stay on the ridge crest or on its right/west side to avoid exposure to the left/east of this hump. From this ridge hump, continue left-ish/east to reach the summit hump. The summit has a large cairn. This is Peak #2 in The Argosy Adventure.
Looking back up the south ridge of Pion Peak. This was my descent route. Livingston Douglas Photo
The large summit cairn atop Pion Peak. Livingston Douglas Photo
Additional Resources
Regions: EASTERN IDAHO->Pioneer Mountains
Mountain Range: Pioneer Mountains
Year Climbed: 2017
Longitude: -113.84389 Latitude: 43.62489