The access for Mount Morrison depends on the route you choose: East ridge or West bowl (also refer to map).
For the standard route, head up Elkhorn Creek, which is signed on the highway. This is the same access as for Mount Idaho.
From downtown Mackay, drive approximately 15.5 miles north on Highway 93. Look for the sign on the right.
From Ketchum/Sun valley, drive the Trail Creek road to Highway 93, then turn right (south). Elkhorn Creek is about 0.3 miles on your left.
When you locate the turnoff for Elkhorn Creek, open the wire gate (and close it after yourself!) and drive up the very rocky road. The first section, about a mile, is driveable in a high-clearance 2WD vehicle. The upper 1/2 mile requires 4WD, but you can walk, right? Just leave your rig where the road gets bad. At the end of the 4WD road, a slight tread leads you up the Elkhorn Creek canyon. Keep your eyes open, as the trail is a little vague in places. It also crosses the creek twice.
AS you drive north, pass the Elkhorn Creek sign mentioned above. In a short distance after, look for a dirt way exiting the pavement on the outside of a slight left-hand bend. Follow the way until you see another way heading straight up hill. After about 400 yards, that way connects with the powerline road. Park here. The way continues up hill, but do not drive further; you are entering a wilderness study area, so should only be on foot.
There are lots of possibilities, but here are two basic routes:
This is the standard route, and the one recommended for climbing in dry conditions.
Round trip distance: 7.8 miles
Vertical gain: 4500'
Difficulty: Class 3
Expected time: 8-12 hours
This gully is best done as a snow climb. The very steep upper bowl could be a true bowling alley in dry conditions. Also note that the entire route follows a potential avalanche path, so only attempt this in stable snow conditions.
Round trip distance: 7.0 miles
Vertical gain: 5000'
Difficulty: Class 3, with a bit of Class 4 depending on how much snow is covering the rocky section.
Expected time: 8-12 hours
Just make sure you close the gate at the highway each time you pass. Please.
Once you leave the highway on the Elkhorn Creek road, there aren't many flat spots. But there is one if you bear left. Look for an abandoned irrigation dam just before the road reaches the creek. The top of the dam is flat and just big enough for a tent.
Alternately, you can camp at Mackay Reservoir, which has lots of camp spots and real toilets!
Or if you're looking for something softer, try the Wagon Wheel motel in Mackay. Very reasonable.