Walking upstream is the general rule and will serve you well for the most part, but in some areas a little more creativity may be involved. Bear in mind that most trails were designed for mules and not the conditions we're experiencing now.
For example: Eagle Creek Meadows is currently a series of lakes with tributaries and outlets all around. The trail plows right through the mess, if you head upstream, you will hit a giant pond. Heading east from Yosemite Falls, a better option is to ignore the trail as early as possible, contour directly around the Eagle Tower/Peak ridge, staying SE of Eagle Peak Creek and the meadows and as high as possible. You rejoin the trail when you finally cross Eagle Creek falling into the valley. It's all pretty much melted out from there to El Cap, I went as far as Ribbon Creek which is a full-blown river, you'd probably need to apply similar tactics there.
I'd approach all meadows and drainages with that in mind. Everything designated by a blue line on the map is now a river; there are thousands of little creeks marked only by contour lines. On the other hand, if you dig cross-country, it's a great time to ignore the dashed lines.
Edited 1 time(s). Last edit at 06/16/2011 02:18PM by QITNL.