That stretch from Salina - Green River - Grand Junction is the longest stretch I've encountered. On my SL350 (2 gal + 1/2 reserve) that 110 miles was about all I could expect before going on reserve, so the "No Services 110 miles" sign gave me pause.
So after refueling in Green River (hit reserve just as I pulled off the highway. I got cocky. I hit reserve just before Grand Junction. But GJ was a ways off the interstate in those days (1972) so I figured i'd press on until there was a gas station in sight from the highway. Just before hitting the Fruita exit the engine quits. But it's downhill into Fruita, so I figure I'll blow through the stop sign on the exit ramp end should be able to coast down into town. As I coast right on through, sure enough, there's a CHP car lurking under the overpass just looking for me to do just that. I explain to him the situation, telling him my tank was dry. He asks "how big is your tank?". So I tell him 2-1/2 gallons. He gives me a ride to the gas station, where I borrow a gas can. The attendant asks me "How much do you want in it?". The cop answers "2-1/2 gallons". All righty then, I see he's checking my story. Fortunately the bike comes exactly full as the gas can is drained dry.
Epilogue: The cop lets me go and even lets me just take off from the highway exit and returns the gas can to the station for me.
But that stretch in Eastern Utah between Salina and Green River remains the longest empty stretch I've come across, with the GR - GJ stretch in second place. But there are lots of 40-50 stretches like that in the Western States.
