I'm on a solo road trip with the goal of rock climbing. Colorado is my home base, but I'm ending the trip in Northern California. Where should I go, and where would I be most able to find partners? I prefer to climb sport, but have a full trad rack as well, so if there's a trad area where I'll be able to find people, please let me know. I'm open to any suggestions!
Bite the bullet and just drive to Squamish. It is worth the drive, especially if you like a mix of sport and trad climbing. The summer weather is great, the camping is lovely, there will be tons of people to climb with (and a fun atmosphere), and the climbing is great too. If I were you, I would drive straight to Squamish and spend the whole trip there, and then head down to NorCal at the end.
Staying a bit closer to home, the "big 3" for US summer sport climbing are Tensleep, Maple, and Rifle. Skip Rifle if you aren't yet solid on 5.12. The others are great for all grades, though. At all 3, temps are a tad warm, but manageable. Good camping, good scene, and people to climb with will be found at all three. The Black Hills (Rushmore, Spearfish), Lander, and City of Rocks are also all worth visiting, although those will all be a tad hot as well. Canmore is excellent in the summer, but the camping situation is a bit tricky/pricey, finding partners might not be as easy, and it is a long drive.