You can start the day in "the" casino and then drive west through some of the best Bakken country in North Dakota and have dinner in one of the nicest restaurants in North Dakota.
I don't know how fast I will get back to update this note, so I at least want to include one link.
If you live in Williston, you can take state highway 1804 east to New Town, and then return via "23" and Watford City.
This is the link to the restaurant in Watford City. This is "Outlaws," the most interesting, exciting restaurant in the Bakken. The restaurant is inside a building complex that seems to take up a city block; it is certainly the largest structure in downtown Watford. The restaurant is part of a bank-movie theater-show-hall-restaurant complex. The link to the bank is here. This link will take you to a "Google satellite" picture of the complex. It's worth the drive from Williston.
The Route from New Town to Watford City
Briefly, you will drive over the newest bridge in North Dakota, crossing from the east (New Town side of the river) and driving west towards the "casino" and Four Bears village. On the New Town side of the river you will be in the Big Bend oil field.
If it's late afternoon and a clear summer day, you are in for a real treat heading into the west, watching the changing horizon of pink clouds and blue skies.
From Four Bears Casino, you will continue west through Four Bears oil field on state highway 23, and into Antelope oil field. Shortly after entering Antelope field you will turn south toward Keene, staying on highway 23. Going south you will enter Spotted Horn oil field from the north and exit Spotted Horn by turning right (west) toward Watford City. (You will come to an intersection but the county road continuing south will alert you to fact you need to turn east or west. Turn west.)
From Spotted Horn oil field you will drive through Blue Buttes oil field, Johnson Corner oil field, Pershing oil field, and finally Siverston field before entering the town of Watford City. Interestingly enough, Watford City, surrounded by oil fields, is not yet situated in a named field. I bet that changes before the current boom is over.