I'm wondering if there are any gas stations in Oxbow Oregon ?
I'm pretty sure the answer is no- there is a gas station at Pine Creek according to google maps. 'Scotty's Hells Canyon Outdoor Supply'. operating hours may be on canyon time...
You're wise to check that stuff out. Eastern Oregon has some of the most remote areas in the lower 48 States. You might call the campground or Scotty's and see if you can get someone to tell you. Often a little dot on a map is a general store with 2 gas pumps out front but if they are out of gas or as mentioned "On canyon time" you could be 50 to 100 miles from the next one.
You're more than welcome. Enjoy the ride.