Paragraph 1.15 in the Declaration of Covenants, Conditions and Restrictions CC&Rs) For Golden Vista RV Resort defines a Park Model as follows:

1.15 Park Model. A dwelling unit defined by the current Arizona Revised Statutes as may be amended from time to time, as built on a single chassis, mounted on wheels, designed to be connected to utilities necessary for operation of installed fixtures and appliances and has a gross trailer area of not less than three hundred twenty (320) square feet and not more than four hundred (400) square feet exterior horizontal dimension in the set-up mode. A Recreational Vehicle, including a Park Model as defined herein, may include appurtenances that have been approved by the Architectural Control Body and have been approved and received a building permit to be constructed in compliance with City of Apache Junction codes.

The Arizona Revised Statures ( 33-1409, definition #14) make it clear that a park model trailer is NOT a mobile home.  Definition #14 is quoted below:

14. "Mobile home": (a) Means either of the following: (i) A residential structure manufactured on or before June 15, 1976, that .... (ii) A manufactured home built after June 15, 1976, originally bearing an appropriate insignia of approval issued by the United States department of housing and urban development. (b) Does not include either of the following: (i) A recreational vehicle such as a motor home, camping trailer, van, fifth wheel trailer or other type of recreational vehicle. (ii) A structure known as a park model trailer that is a structure built on a single chassis, mounted on wheels and designed to be connected to the utilities necessary for the operation of installed fixtures and appliances and that has a gross interior area of not less than three hundred twenty square feet and not more than four hundred square feet when prepared for occupancy.

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Park Model - A good alternative to RVing
A Park Model is a cross between a Travel Trailer and a Mobil Home. Since Travel Trailers were a place that people lived in as a retirement home, the industry developed a somewhat larger and more livable unit with a sliding glass door and Mobil Home style appliances, that they called a Park Model. These units resembled a travel trailer, but as time went on they developed the appearance of a small apartment size house with vinyl siding, conventional house entrance door and a with a peaked, shingled roof. There is no 12 volt system since the "RV" was designed to be semi permanently set up and contained city water utilities and 120 volt appliances. Officially they are classified as an RV since they come with wheels and are less than 400 square feet. Once they are setup and established on the site it is inconvenient and difficult to move them. However, they can be moved if you want to foot the cost. Park models are handled like a mobile home, delivered by professional drivers set up and anchored down by professionals. All the utilities (electric, water and sewer) are installed in a permanent fashion.

Back in the fifties travel trailers were small, usually under 30 feet and when people thought about living full time in one the manufacturers came up with a house-trailer that could be moved by a truck from place to place. The idea was that the unit would stay in one place for long periods of time. Today Park Models are designed for quality, but with less emphasis on mobility.