Epic ride for the two of you, pre-congratulations.
You need to include Utah, as rico pointed out. Zion & Bryce as a minimum, should not be missed. An easy reroute back to the west across Nevada and through Yosemite will be quite simple.
You'll be hitting the Mojave desert and it is heating up a bit. The key is to keep skin exposure is a minimum. If you don't always wear a riding jacket, at least put on long sleeve shirts through the desert's.
Welcome to the U.S.!