Few things I found here in Wisconsin, not sure what your state requires but im sure there is probably something similar.
When do I need a Wisconsin CDL instead of my regular Wisconsin Drivers License?
A Wisconsin CDL is required if you operate any of the following CMV's . . .
1. A vehicle with a manufacturer's gross vehicle weight rating (GVWR) of more than 26,000 lbs.
2. A vehicle towing a unit with a manufacturer's GVWR of more than 10,000 lbs. when the GCWR exceeds 26,000 lbs.
3. A vehicle used to . . .(a.) carry 15 or more passengers (excluding the driver), or (b.) carry (15) or less people (including the driver) when carrying children to or from school and home regularly for compensation.
4. A vehicle carrying hazardous materials in amounts requiring placarding.
Ok, with that said.
Are there any exemptions to being required to have Wisconsin CDL?
Yes, a few . . .
1. Active Duty Military . . . with military licenses operating military vehicles.
2. Firefighters . . . meeting approved training standards and operating authorized emergency vehicles.
3. Farmers . . . in certain cases.
4. Individuals ....operating motor homes or other vehicles used exclusively to transport personal possessions or family members, for non business purposes.
Also, a CLASS A . . . allows you to operate vehicles which tow trailers or other vehicles with a GVWR over 10,000 pounds. A Class "A" license also allows you to operate Class B and C vehicles.
CLASS B . . . allows you to operate single vehicles with a GVWR of 26,001 lbs or more OR a gross combination weight rating (GCWR) of 26,001 lbs. or more, towing trailers/vehicles rated at 10,000 pounds GVWR or less. A Class "B" license also allows you to operate Class C vehicles.
I dont think anyone needs a Class A for recreational use, unless you plan to run a business or use it for business purposes in which case you would already have/need a CDL anyway. In most cases if your state requires you to obtain a CDL, a Class B is more than adequate.