According the Minnesota Statute 160.2715, "(a) Except for the actions of the road authorities, their agents, employees, contractors, and utilities in carrying out their duties imposed by law or contract, and except as herein provided, it shall be unlawful to:
(1) obstruct any highway or deposit snow or ice thereon and (b) Any violation of this section is a misdemeanor."
This means, in laymen's terms, you can't push snow across the road or into the street to get it out of your driveway.
The law is very specific on this issue. You can get fined for pushing snow across the road -- be it state, county, city or township.
According to the MN DOT website, "Snow removal operators are advised not to push snow onto public roadways."
The Minnesota Department of Transportation reminds all snow removal operators that it is unlawful to deposit snow on or next to a public highway or street.