From the parkinglot at the NE end of Convict Lake, head directly up the slopes on the lakes SE side. The first part is quite steep and sandy, but this eases after 400 ft of climbing. There is an inlet to the lake that comes the south, draining the east side of Mt. Morrison. Follow the same direction as the creek, but stay high on the ridge to the left (east). The creek is a jumble of boulders, whereas the ridge has firmer footing.
The hiking here is often hot - there is no shade, and much scrub. After two miles the canyon turn to the right, closer to Mt. Morrison's east side. Follow this to a small tarn, then head west, bringing you abreast the East Slope.
There are several routes you can take to the summit that remain class 2. The easiest route seems to be on the right side of the East Slope. A buttress splits the east route, the left side being a wide bowl, and the right side is more a chute/slope. There is a faint use trail that helps in climbing much of the steep, loose sand and scree on the right side. Eventually you'll need to cross over the buttress to the left and climb the remaining distance up the wide bowl.
Alternatively, at the base of the East Slope you can continue south a short ways and enter the bowl directly from the bottom. The lower half is steep and requires some (not so difficult) route-finding to keep it class 2. But the rock is very loose here, and the going is slower going this way than sticking to the right side.
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