You could try the inlet or outlet at keho,
The inlet at Ridge may be another good option.
Off the Dam at St.mary.
Those 3 options if you want to try for walleyes.
If you want to fish for trout you can head to nicholas sheran, riverstone which are both in the city. Or head out to Mcvinny, Keenex, or McQuilan.
If you want to fish for pike you can try henderson, nichols sheran, Park Lake, Keho, ridge or St.mary.
If you want to try your hand at some sturgeon you could walk along the Oldman river in town and just out a pickerel rig or sturgeon rig with minnows or worms. Any slow moving deeper hole will usually hold a few different species of fish.
Hopefully this helps you out.
Nate