What tahunua describes is about all I've encountered in Idaho and Wyoming, except that those check stations in Wyoming were set up at low speed choke points or major intersections, with wardens actively watching traffic and actively flagging down hunters (aside from generous signage telling all hunters to stop).
In Utah, however, I've encountered the 'DUI' style check points where major dirt roads tie back into highways, and they stop every vehicle - at least long enough to just peak through windows or into the truck bed, to see if the person may have been hunting.
In any of the above states, they will come after you (if they have the manpower available) if they see evidence of a game animal, or enough evidence that you were likely hunting, but you don't stop at the check point. I've seen them do so in Utah and Wyoming. And...
In a previous post, I said I hadn't ever stopped at a check point in Idaho. That's true, but I did encounter a warden from one once. Coming home from a family member's hunt in Utah, a couple years ago, there was a check station (I think more for CWD inspection) set up just inside the Idaho border. I blew past it, since I wasn't hunting (and hadn't been) ... even though I had hunter orange visible and a pack frame strapped to a 4-wheeler in the back of a muddy truck. (For anyone that has traveled northbound on I-15 into Idaho, over the last 7-8 years, this was at the rest area that doubles as the watercraft inspection location, and has a dozen signs on the highway indicating such.)
I stopped at the gas station in Malad, ID (about 6 miles further up the highway). As my son and I were getting out to pump gas, a Fish and Game truck pulled in behind me. Summarized exchange from memory:
F&G: "What are you doing, dude?"
Me: --"Gittin' some gas. What's up?"
F&G: "You blew the check point. You know that's a [some monetary amount]-dollar ticket, right?"
--"I wasn't hunting."
F&G: "It sure looks like you were."
--"Yes. Yes, it does. That's fair. But I wasn't. I was in Utah providing use of my 4-wheeler and on standby as a pack mule in case an elk was dropped by family."
F&G: "You mind if I poke around a bit and take a look? Do you have any firearms, besides the one on your belt?"
--"Yea, there's a loaded revolver there and a rifle with a full magazine behind the seat [motioning to where they were]. You can look all you want, as long as you start here..."
I grabbed a fuel receipt out of the driver's door pocket, showing that I had been in Heber City, UT (150 miles away) about 2.5 hours prior.
We exchanged a few words, and then pleasantries. And then he took his leave without digging further, after saying, "next time, tell the story at the check station, please; so we don't have to chase you down for it."