I've been to both locations.
One thing to keep in mind is that those two locations are very touristy. Buses bring in tourists by, well, busloads and common areas are pretty busy. Unless you go in odd hours or deep into the canyons, there will be people everywhere. While not exactly a dangerous (people wise) place, you won't be over burdened with equipment either. I wouldn't be surprised if you set something down, and get distracted by needing to set something up or mistakenly walk away, things might just disappear. Something to think about.
When I was there, I had more needs for wide than long lens.
If it were me, I'd take one digital and one B&W film (that's how I operate) both with wide to normal zoom or prime. Then I'd probably take orange or red filters for B&W work. I'd take one path with the former, then come back for later. For some reasons, I can only do one media type (color or b&w) at a time. If I try to do both by switching often, I tend to produce very mediocre images. I don't know about you.