TX (obviously), NM, AZ.... TX LTC is good to go and no limits on magazine capacity that I'm aware of. NM has some different off limits places that you can find on handgunlaw.us if you plan to stop in NM. I Make the drive to Tucson occasionally to visit family. That part of the trip is usually about 14 hours including gas and restroom breaks. TX is BIG!.
I'd refer you to handgunlaw.us for current information about CA. Last time I brought a gun there was years ago. I flew into Bakersfield, kept my gun disassembled (slide removed from frame) in a locked case until we crossed the AZ border on the drive back. No mags over 10 rounds, IIRC. Was helping a friend move from CA.
ETA: Link opens PDF. see page 9.
https://handgunlaw.us/states/california.pdf
