Much of this unit is part of the Frank Church-River of No Return Wilderness on the south side of the Salmon River and west of the Middle Fork. Elk tags are limited but sold over the counter, mule deer tags are not limited but hunters must apply in the annual drawing and whitetail tags are sold over the counter and are not limited.

With low deer and elk numbers, hunting in this unit is challenging. Much of the terrain is remote and difficult to reach. Wolves have had an impact on elk herds, but hunters still kill mature bulls and bucks yearly.

On the south side of the Salmon River from the Middle Fork to Mackay Bar, this unit is mountainous and remote. It is mostly in the Frank Church-River of No Return Wilderness in the Payette National Forest. Most terrain is steep and rugged, but some drainages have flat to moderate inclines, such as Chamberlain Basin and Whimstick Creek. Some prominent peaks include Papoose at 8,989 feet, Twin Peak at 9,258 feet, Wolf Fang at 8,932 feet and Rattlesnake at 7,791 feet.

The mountains that rise along the Salmon River and the Middle Fork of the Salmon River are open, and some interior mountains also have large open areas and scattered trees. Short grasses, brush and forbs cover most of the lower mountains in the unit, and some large grassy meadows are at middle elevations. The higher peaks are generally open, while north-facing slopes and many eastern slopes are heavily timbered by spruces, pines and firs. Parts of the unit, such as near Twin Peak, have large canyons and numerous slopes that have been denuded of trees by forest fires.

Hunters camp along forest roads outside the wilderness in the southwestern arm of Unit 20A. Some hunters contract with outfitters and stay in lodges or cabins in Chamberlain Basin, Mackay Bar and Whimstick Creek. Many outfitted hunters and some private hunters camp in tents packed in by horseback.

In good weather in September and sometimes in October, hunters can drive four-wheel-drive ATVs or UTVs down the Mackay Bar Road from Dixie Point on the north side of the river to the Mackay Bar Bridge. Full size four-wheel-drive vehicles can navigate the trail, but OHVs are much more comfortable to ride because the road is rough. Flying services include Sawtooth Flying Service, Arnold Aviation and McCall Aviation. Several outfitters have clients fly into landing strips, such as one at Chamberlain Creek and another at Whimstick Creek, and then take their hunters to hunting lodges or to remote hunting camps. Primitive roads in the southwest part of the unit can be reached by four-wheel-drive vehicles from primary roads that pass Warm Lake and Deadwood Reservoir.