Here's some activities to visit in North Dakota that will cost you little or no money. 

So you want to get away for a couple of days and clear your head. Here's some ideas that won't cost an arm and a leg:

You're into nature and you want to just relax, partake or maybe take the date on a nature walk. A cool  place to check out is Cross ranch nature preserve up in Hensler.  There you can bird watch and and also check out the Buffalo from afar (dunno, I kinda want to pet one though). Cost:$0

If you like wine or your significant other does, Maple River Winery in Casselton is a good spot to check out ... free admission and you drink wines like Choke Cherry Wine, or Dandelion wine lol  I gotta try that juice! This is a great spot to go with three women in what I like to call a Favored foursome.The Cost :$5

Here's one more guys:

The North Dakota Beer and wine trail.  this one takes you all over the state to 16 breweries , 14 wineries , 14 vineyards, 3 distilleries , and 2 Cideries . This could be one of those all summer bucket list types of tours. Or like a get in the van an go for a week  Easy Rider style. Cost: Very little 

North Dakota has plenty to offer as you know and it really is a lot more cost effective than I thought.