Here is South Dakota's ruling:
32-19-9. Chains or cables required in addition to coupling--Fifth wheel and kingpin coupling--Violation as misdemeanor. Every trailer which shall be towed on the public highways at a speed in excess of twenty miles per hour shall be coupled to the towing vehicle by means of a safety chain, chains, cables, or equivalent devices in addition to the regular trailer hitch or coupling. This requirement does not apply to a semitrailer having a connecting device composed of a fifth wheel and kingpin assembly meeting the requirement of the interstate commerce commission, nor to a pole, pipe, casing, log, or piling dolly. Any person who violates this section is guilty of a Class 2 misdemeanor.
32-19-10. Safety chain slack and coupling--Violation as misdemeanor. No more slack shall be left in safety chains, cables, or equivalent devices than shall be necessary to permit proper turning and the safety chains, cables, or equivalent device shall be so connected to the towed and towing vehicle and to the drawbar to prevent the drawbar from dropping to the ground if the drawbar fails and shall be of sufficient strength to control the trailer in event of failure of the regular trailer hitch or coupling. Any person who violates this section is guilty of a Class 2 misdemeanor.
Again SD talks about drawbar just like Nebraska!
Your two states need to get a life. Now for South Dakota can in apply it's laws to vehicles licensed out of state is an issue! I know license requirements and tonnage refers back to the state one in licensed in.
I see Reese has safety chains that pin onto the bed rails.
Cummins12V98, did you have your safety chains attached when you were in SD? If you license in SD, you better get those safety chains ordered ASP!
I would also note that the king pin on recreational trailers is the same standard size and dimension as a semi trailer. So does it meet the requirement of the interstate commerce commission? A semi trailer is defined as one where the tow vehicle carries some of the trailers weight!
Additionally the design of some 5th wheel hitches and trailer pin boxes would lead to interference between them and safety chains.
SNOKING