It will vary from state to state on what the states will permit for. The farther east you go the less you get. A lot of states will only permit the trailer as a standard 2 axle trailer. Depending on the axle spacing and width you can 60k or more in some states. CA, NV and AZ are very common - 10’ wide axles and 6’ axle spacing. Some states will call them trunnion axles.
Here is the information from the. Roth Dakota permit site. It looks like you must give them a vehicle diagram with tire size, axle spacing and axle width to justify the weight you are requesting - probably 60k.