the embodiment illustrated in fig1 the primary support structures 112 114 extend substantially vertically from the chassis 106 bend and extend substantially horizontally across the width of the chassis 106 and then extend vertically to the chassis 106 the support structures 112 114 could be replaced by support structures of various shapes and sizes to obtain the desired characteristics including roof line for example the two support structures 112 114 shown in fig1 may be replaced by four posts extending vertically from each corner of the chassis 106 in some embodiments support structures 112 114 may be unnecessary as the first and second frames 110 115 or the first and second walls 140 142 may adequately support the covering of the mobile shelter 100 not shown in fig1 in some embodiments one or more primary support structures may be hingeably or releaseably attached to the chassis 106 in the embodiment illustrated in fig1 primary support structures 112 114 are connected to the chassis 106 at hinges 103 hinges 103 allow the primary support structures 112 114 to fold inward and lay substantially parallel to the chassis 106 when the mobile shelter is in its third configuration in some embodiments the primary support structures may be connected by one or more top support 130 which may extend across the top of the structure between the primary support structures in some embodiments the top support is parallel to the base 109 the primary support structures 112 114 and top support 130 may be formed of any rigid material substantially capable of maintaining its shape when exposed to the elements for example.