Take some binoculars. Big bend is one of the few places in the states where you can get spectacular dark sky views. (Astronomy)
With binoculars you should be able to see all kinds of interesting things, and if you have the inclination to bring a decent scope 8" mirror and up, you can see galaxies all over the place. I've been wanting to get out there for a year now but it's a 10+ hour drive for me.
Have fun.
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