This guide is for general information only and is not legal advice. Laws change — verify current rules with your state DOT or a licensed attorney before relying on this for any legal matter. Read full disclaimer.
The rule
Minnesota requires lamp on the front emitting a white light visible from a distance of at least 500 feet to the front, required during the hours of darkness as defined in minn. stat. § 169.011. For the rear, red reflector of a type approved by the minnesota commissioner of public safety, visible from all distances from 100 to 600 feet to the rear when directly in front of lawful lower-beam headlamps. a red rear lamp visible from 500 feet may be used in addition to the reflector. The rule applies whenever it is dark. See Minn. Stat. § 169.222 subd. 6 (Bicycle equipment).
The cheapest way to stay legal in Minnesota is a USB-rechargeable front white light and a rear red light or reflector that meets the spec above. A $30 light set covers it.