As you said, first and foremost where you fly obviously depends on the airline you fly for and their operations. Are we talking small commuters like Cape Air or Silver Airways? If so then you may only cover a state or 2. Larger Regional? When I was at ExpressJet we flew virtually everywhere in the continental US, Mexico, Canada and some Caribbean. There are Nationals like JetBlue and SouthWest who do the US and some South America and Legacy Majors like United and Delta who literally fly around the world. Where you fly will also depend on the airplane you’re on. If you fly for United but are on the 737 it’s really the US, Mexico and Canada. If you’re on the 777 you’ll go much further (Europe and Asia) but there are far fewer destinations that airplane may visit. I’m with Hawaiian and the 717 doesn’t leave the state of Hawaii. I’m on the A330 now and we go from JFK to PEK and many places in between. Now as for your individual schedule like EVERYTHING at the airlines you’ll bid for it and what you get is largely dependent on your seniority (btw, we bid our schedule by the month). Certain trips may be more senior because they’re “better” or more popular but might also be due to what that trip pays (longer pays more). Yes you could get “stuck” running the same route but most guys like running the same route. Others don’t. Keep in mind (again depending on the plane you’re on) that many aircraft have very few destinations or routes. I had a friend who dreamed of flying the 777 for Continental back in the day but then found out that plane only went to 6-7 locations. Rome is great but after the 20th time anywhere might get boring or maybe you’ll make friends and can’t wait to get back there. It’s all up to you and what you like.