86.19 (1) Except as provided in sub. (1m), (1n), or (1o), or (1p) or s. 84.01 (30) (g), no sign shall be placed within the limits of any street or highway except such as are necessary for the guidance or warning of traffic or as provided by ss. 60.23 (17m) and 66.0429. The authorities charged with the maintenance of streets or highways shall cause the removal therefrom and the disposal of all other signs.

86.19 (1p) (a) In this subsection, “ tribal nation welcome sign” means an official sign erected and maintained by a federally recognized American Indian tribe or band in this state that the tribe or band determines is necessary to inform motorists of the territorial boundaries of the Indian reservation or other land held in trust for the tribe or band.

(b) A federally recognized American Indian tribe or band in this state may erect and maintain within the right-of-way of any highway within the boundaries of an Indian reservation or other land held in trust for the tribe or band a tribal nation welcome sign. No sign under this subsection may be placed within the right-of-way of a highway designated as part of the national system of interstate and defense highways. A sign placed under this subsection is not a traffic control device and is not subject to the provisions of the Wisconsin manual on traffic control devices adopted by the department under s. 84.02 (4) (e).