[invoman]

I KNOW it's not a Federal Trademark, he MAY have a STATE trademark in Minnesota for "Minnesota Fishing", does this cross State lines?

[JAWs]

If he has a state trademark, it won't cross state borders.

Also Minnesota Fishing may not be trademarkale as it is so highly descriptive and generic.

[CharacterCounts]

Can't tell you about Minnesota law, but in Michigan you cannot trademark the words Minnesota Fishing. You can only trademark a specific logo containing those words.