Been researching (lightly) getting a HAM license and setup for the jeep. The entire time that I've been looking into this, I thought I would have the ability to communicate with others on the trail that are using a CB. But I just came across something that said it could be done but would be illegal. Did I read that right?
T'is true.
Though you can usually make a radio that works on the 10-meter ham band work on CB also, to do so is illegal per FCC rules.
Will you get caught if you do it? That I couldn't say... (you'll have to do so at your own risk) However I suspect that if you used it in a responsible manner so as to not bother anyone else (keeping your tx output power around 4 watts for example), no one would be the wiser.
Lets face it, how many times does someone on a run have to relay a message back and forth because the range of cb just doesn't cut it. .
Almost never in my group.
Seems to me it would be just as easy (if not easier) to push people toward simply junking the crappy CBs with muffly-sounding microphones and dinky stub antennas they bought at Wal-Mart for a better CB rig vs. getting everyone to switch over to a different radio service where not only do you have to get new radio gear anyway, but study for a FCC license test as well...
This is not to say a ham radio running thru a hilltop repeater doesn't have it's advantages, certainly there are some perks to it that CB doesn't offer. But clearly something is wrong if people are unable to get a message across from one end of the vehicle group to the other.
I frequently make contacts on CB (often it's someone else that hears our group talking and breaks in asking where we are at). I've talked maybe a hundred miles out from hills with my Uniden and just a 5½ foot antenna centered atop the vehicle roof (using legal 4 watt power output). Under more normal conditions (not on a hill), 20 miles is pretty typical range to someone at a base station, and 10 miles for mobile to mobile. All you need is a decent rig with a good antenna.

Of course once in a while there are occasions where a leaky power line in a town somewhere creates S-9 static interference in your receive which reduces your range (a drawback of the HF (27MHz) band. I've had my VHF affected by this too, though usually not quite as bad). Moving a block or so off the main drag thru town (away from the lines) often helps in these cases.