Okla. Stat. tit. 47, § 47-1-181.1: Travel trailer

Travel Trailer.

Any vehicular portable structure built on a chassis which is not

propelled by its own power but is towed by another vehicle and is

used as a temporary dwelling for travel, recreational or vacational

use. A travel trailer shall have a body width not exceeding eight

(8) feet in travel mode and an overall length not exceeding forty

(40) feet, including the hitch or coupling.