Doing a google maps search of “Philadelphia to San Francisco”, I think the Utah suggestions are wonderful.
But the first several hundred miles are going to be pretty boring. I’m going to suggest altering the route a bit to head through:
- Washington DC - Okay, you may be from Philly, but it’s a wonderful must-see for any American trip, and there’s a bazillion things to see and do.
- St. Louis Arch - Not much of an original suggestion, but the map is still pushing me north and through St. Louis - It’s a cliched tourist site, but it’s an easy hour long tour, and interesting, considering the trip ahead of you.
- Kansas City BBQ - I’m not going to get into a BBQ debate, but KC BBQ is excellent, regardless of your preference. And as a bonus, it’s actually on the route. Stop by Arthur Bryants or Gates BBQ, both have easy exits from the highway. (Get ribs at Gates, and a sandwich at Bryant’s - I prefer the beef and pork combo.)
- Denver - There has to be something to see here, right? Locals want to chime in?
- All the Utah stuff and beyond.