As dry as Texas as been I'm not sure you could even make mud there with less than a frog strangler thunderstorm. As for Cali, well we had some rain and the dirt did get a little tacky. Then they passed an ordinance against mud and hired 10,000 union dirt dryers with huge state pensions to dry it all up. Now we are even more in debt but we have no mud. 70 today, partly cloudy, I'll walk over to Fashion Island and eat at one of the outdoor sidewalk cafes for lunch. Pretty nice.
Seriously the desert and the mountains have some phenomenal and beautiful wheeling areas and if you catch it just right you can find some mud. I came back from one of the Mojave road trips after it had rained quite a bit and Tustin had the truck on the wash rack for 30-40 minutes with the high pressure hose trying to get enough mud off the truck so they could work on it. I think they got about an acre of dirt out from under the truck. Doesn't happen often though.