Minnesota
Direct link to section code
section 169.70
REAR VIEW MIRROR.
Every motor vehicle which is so constructed, loaded or connected with another vehicle as
to obstruct the driver's view to the rear thereof from the driver's position shall be equipped with
a mirror so located as to reflect to the driver a view of the highway for a distance of at least
200 feet to the rear of such vehicle.
History: (2720-259) 1937 c 464 s 109
Super Vague but that means that I can get rid of outside side mirrors and install them inside the cabin.
I added the info myself to the Wiki