Ok, your average terrain-only based viewshed (view is from a road to the southeast, viewshed is in cyan):

Note that based on these estimates, we should be able to see most of the valley walls from this little slice of road.  I don’t buy that.  That section of road is pretty closed in with trees.  Let’s add them:

As you may see, just a little cyan in the southeast mostly along the road.  Here’s where you can see the trees occluding our view of the viewshed a bit.  But, it’s a first good stab, even with such boring results… .  I’ll have to get that section of road in here that peeks out over the gorge.  But first, I’ll have to see if I can get tree stem locations from the lidar, so we can trade up for some veracity in our analysis.  Stay tuned.