Hi there! Experienced hiker here, with a permit to climb Whitney in September. I was wondering what the trail surface is like: smooth compacted dirt, fist-size loose rocks, gravel, sand, scree, boulders requiring scrambling, etc.? A combination? We have all of those here in the Pacific Northwest. The Whitney climb will be my first time hiking in that part of California, so I'm trying to get a sense of what the trail surface is like late summer.