CB is a good choice for offroading because of its lower 27 MHz frequency. It gets out easier and has a longer range than higher frequencies do. GMRs. FRS, 2m or 440 MHz ham radios are cool but they operate at a significantly higher (2m ham is at 145-147 Mhz) frequencies which don't do well except on flat terrain. Ham radios can get around the flat terrain issue with repeaters that sit on mountain tops to repeat their signals over a wider area but not all remote offroad areas have repeaters in them.
So while I have a 2m ham radio in my Jeep, CB is my first choice for offroading. I'd say I use my CB 99% of the time and my ham radio only 1% of the time I'm offroad.
Here's my setup... the Yaesu FT2900R 2m ham radio is on top, the CB is a Uniden Pro-520XL.
Edit: Whoops, that's my old setup from my TJ that was stolen in March. The top radio is an ICOM V8000 in that pic. I guess I don't have a pic of what's in my replacement TJ but it's very similar other than having switched brands from the ICOM to the Yaesu ham radio.
Also the police no longer monitor channel 9 on the CB.