Yes, anglers 17 and older do need a valid All Species Michigan Fishing License for the days that you plan to fish.  Either daily or annual all species license is required by the State of Michigan.  Click on the link here and follow the prompts.  http://www.mdnr-elicense.com/welcome.asp  If you choose, you can stop by any license dealer in Michigan as well.  Virtually all sort shops will be able to sell to you, including Meijer and Walmart