Mountain Directory West (available online) clearly indicates 190 is a route that I would not take as it describes the grades and lengths. Even taking 178 up still leaves the eastern pass and not for us.
Gas Buddy is my first source for stations. Sometimes I'll look up truck stops online. "gas" stations can be an issue with limited access or 4 wheelers going inside to buy food and leaving their vehicles at the pump, etc. But if you use gas then you likely deal with this often as truck stops often don't have RV lanes.