South Loon Mountain is a remote peak in the mountains above McCall, Idaho. These mountains are mostly granite, with moderate south slopes and precipitous north sides. The route described here for South Loon takes the moderate south slope.
Although there are trails in this area, they are often not maintained, so can be hard to follow at times. However, if one is skilled at navigation the terrain lends itself to cross-country travel (a euphemism for the dreaded "bushwacking").
The route here, car-to-car, is approximately 14.5 miles with a climb of over 2500'. Due to the need to cross a ridge on the way, there is about 4200' of actual gain. So for most folks this is a big day. For faster hikers, expect this to take about 7-9 hours.
From the trailhead, follow the trail to Duck Lake, about 1 mile and 430' gain.
Walk north up the valley past Duck Lake to a trail intersection at about 1.2 miles farther and 200' higher. Turn right and head uphill.
After another mile and 900' gain, you will top a ridge. Descend the other side on marginal trail, then leave the trail (if you are still on it), heading northwest. Pass the southern side of the two unnamed lakes, then continue to angle northwest as you climb gradually. Eventually, you will meet another trail.
Follow the trail north until you reach the south ridge of South Loon. From here, follow the ridge, more or less, to the summit.
This climb can be accessed in any car, assuming you go when the road is snow-free. The snow generally leaves the upper portion of Lick Creek Road by mid-June. However, in any season it is a long, bumpy drive.
First, get to McCall. Either take Highway 55 north for about 100 miles from Boise, or come south from Riggins and New Meadows.
From downtown McCall, take the Lick Creek road, also signed as the turn for Ponderosa State Park. Turn right after the golf course, then take another right off the pavement (signed) in about three miles.
From downtown McCall, it is about 23 miles to Lick Creek Summit. Drive down the other side about 1/2 mile to the Duck Lake trailhead. There is room for quite a few cars, and the trailhead also includes a good toilet.
No red tape.
However, this is within big-game hunting area, so check the regulations and wear bright colors.
The closest official campground that is worth anything is the Lake Fork Creek campground, about 10 miles before the summit. The campground is quite nice (although primitive), but also quite popular. Normal Forest Service fees etc. apply.
The map shows a Black Lee campground, but it's mostly just a dirt pull-out, and not recommended.
However, there are numerous unofficial campsites along Lake Fork Creek.
Or you can stay in McCall at either one of the many hotels, or try Ponderosa State Park (usually requires reservations).