We dumped at the Pilot/Flying J a few miles north of Beehive on Hwy 89 (our way to Lone Rock). I'm pretty sure they had water available to fill tanks there too, but not positive as we didn't need any right then. I'd call and check to make sure. The dump was free a couple years ago.
Grocery store in Page, only a mile away. You can dump RV tanks and refill fresh water about 10 miles down the street at the Lone Rock Beach campground.