According to an AAUW study, Minnesota ranks 23rd highest in gender wage gap. Median wage for men is $50,081 and median wage women $39,289 that's 78%. All statistics include women and men over the age of 16 and working full time.
#1 is Washington, DC where women make 91% of men's wages and #51 was Wyoming where women make 61% of men.
Here's the link to the AAUW press release.
The Pay Equity Coalition of Minnesota understands the complexities behind the wage gap. They include under valuing of women's work in the free market (women are clustered in jobs such as administration, clerical, managerial, teachers, nurse) but also includes factors such as family responsibility, wage negotiation skills, glass ceilings, and aversion to risk.