A post making the rounds in hunting and thermal optics communities right now shows a hunter who mounted a gimbal stabilizer to the roof of his truck, dropped an iRay thermal monocular on top, and essentially created a vehicle-mounted thermal scanning rig for sweeping fields at night — all from the driver’s seat. The setup looks slick. It’s also the kind of thing that could land a Montana hunter in serious legal trouble depending on exactly how, when, and where it’s being used.
Before you start pricing out magnetic roof mounts and thermal units ahead of spring predator season, here’s what Montana Fish, Wildlife & Parks regulations actually say — and where the gray areas get dangerous.
The Spotlighting Law Is Broader Than You Think
Most Montana hunters know spotlighting is illegal. What fewer people understand is how broadly that prohibition is written. Under Montana Code Annotated 87-6-210 — which applies specifically to big game and other game animals — it is unlawful to use a light to spot, locate, or observe wildlife from a vehicle in combination with a firearm. The key phrase is “spot, locate, or observe.” You don’t have to shoot anything. You don’t even have to have a gun in your hand. If you’re running a roof-mounted thermal scanner from a truck on a rural road outside of Choteau at midnight and you’ve got a rifle in the cab, you are in a legally precarious position — full stop.
Whether thermal imaging devices qualify as “lights” under that statute is a legal question that, to our knowledge, has not been definitively tested in Montana courts. However, from a practical standpoint, the risk is real: thermal units emit radiation in the infrared spectrum and are used specifically to locate animals. Montana FWP wardens are unlikely to split hairs about wavelengths when they pull up behind your truck at 1 a.m. on a Forest Service road outside of Lincoln. The warden interpretation — that a thermal device used to spot game from a vehicle functions like a light under the statute — is the risk you’re managing, even if the legal question isn’t fully settled.
What Is Actually Legal: Predator and Varmint Hunting
Here’s where it gets nuanced, and where some hunters do have legitimate use cases for thermal setups on vehicles.
Montana does allow night hunting for certain predators and varmints — specifically coyotes, which can be hunted year-round with no closed season, and prairie dogs on private land (though some counties or specific land management situations may carry additional local restrictions worth confirming before you go). There is no closed season or time-of-day restriction on coyote hunting in Montana, which means a thermal scanner used to locate coyotes at night is not automatically illegal.
It’s also worth noting that MCA 87-6-210 targets big game and game animals — and coyotes don’t fall into those categories under Montana law. That distinction matters for how the statute’s spotlighting prohibition applies to predator hunters.
However, the spotlighting statute still applies to the method when game animals are present or could be implicated. If you are using that roof-mounted thermal to locate a coyote and you have a firearm accessible in the vehicle, you are treading carefully in gray legal territory. The safest and most defensible approach is to use the thermal for glassing from a stationary position with the vehicle off, then exit the truck before making any move toward a shot. Shooting from or immediately adjacent to a running vehicle with an active scanning device still looks like spotlighting to a warden — and that appearance matters.
For coyote hunters working the prairie east of the Highwood Mountains or the river breaks along the Musselshell, the practical advice is simple: use your thermal to glass from a fixed position the same way you’d use a spotting scope. Don’t drive and scan simultaneously. Don’t have a chambered firearm while actively operating the device from a moving truck.
Game Scouting Is Its Own Legal Minefield
Even if you’re not hunting, using a vehicle-mounted thermal system at night to scout game animals — elk, deer, bears, turkeys — can draw warden attention. It’s important to understand that Montana FWP’s electronic scouting restrictions are specifically aimed at devices that electronically transmit the real-time location of game animals to a hunter — think trail cameras that push images to your phone or networked scouting systems. A roof-mounted thermal monocular, used passively without any transmission component, does not meet that definition under current FWP regulations.
That said, using a vehicle-mounted thermal to inventory elk locations on a drainage the night before an archery hunt occupies murky ethical and practical territory. It’s the kind of activity that generates complaints from other hunters and can draw warden attention, even if it doesn’t fit neatly into the transmission-device prohibition. When in doubt, call your regional FWP office and ask directly.
With spring bear season opening in April across much of the state — including popular units in the Swan Valley, the Bitterroot, and the Rocky Mountain Front — and turkey season following close behind, now is exactly the time when thermal optics get more use. Don’t compromise your season before it starts.
Practical Guidance Before You Rig Up
- Call your regional FWP warden. Seriously. Montana FWP has regional offices in Missoula, Great Falls, Billings, and Kalispell. Wardens will answer specific questions. A five-minute phone call beats a $1,000 fine and a license suspension.
- Use thermal optics from stationary positions. If you’re coyote hunting at night, park the truck, turn off the engine, and glass the same way you would during the day. Exit the vehicle before taking a shot.
- Don’t mix game animals and vehicle-mounted scanning. Even if your intent is predator control, using a thermal rig in areas with deer, elk, or other game animals increases your legal exposure significantly.
- Know the difference between observation and electronic transmission. Passively viewing animals through a thermal device is different from using devices that electronically transmit locations — but context and timing still matter.
- Document your hunt plan. If you’re running a legitimate predator control operation on private land, have landowner permission in writing and be ready to articulate your methods if contacted by law enforcement.
Thermal technology is incredibly effective. It’s also new enough that enforcement interpretation is still evolving. The smart play is to use it conservatively, transparently, and well within the boundaries of what Montana statute and FWP regulation clearly allow. If you’re not sure whether your setup crosses a line, assume it does — and adjust accordingly.