I was out in the area for work, and managed to arrange to take a short trip with Ctein and Paula to a couple of local cool places. Getting to the bridge just at sunset was pure luck, not planning -- none of us had been to that particular overlook before.
Muir woods is dark. A tripod would have been really useful (I don't know what the rules are; it's crowded enough that they probably restrict them somewhat). I did make use of my beanbag quite a lot, both there and at the bridge (at the bridge I made exposures up to something like 6 seconds). I also used high ISOs -- nothing below 400 in the woods. As you can see in a few of the pictures, it was sunny -- up above the trees. Redwoods definitely modify their local environment.