Wyoming winters are already tough enough. Your eyelashes freeze, your coffee turns into a coffee-sicle, and your truck occasionally questions its will to live. Fortunately, Senators Cynthia Lummis (R-WY) and Dan Sullivan (R-AK) just teamed up on a bill that speaks directly to anyone who’s ever tried starting a diesel engine at –20°F and thought: “This feels like a test of character.”
Their new proposal, the Cold Weather Diesel Reliability Act of 2025, aims to fix a classic case of federal rules written by people who think 28 degrees counts as “brutal.”
So… What’s the Problem?
If you’ve ever had your diesel engine fail you on a frigid Jackson morning, you’re not imagining things. Many trucks rely on Diesel Exhaust Fluid (DEF) systems that freeze at around 12°F. When that happens, the EPA’s current regs can force the engine to slow, derate, or shut down, even if everything else under the hood is perfectly fine.
It’s the bureaucratic equivalent of the truck saying, “I could work, but the rulebook says I’m supposed to be upset right now.”
Lummis and Sullivan are basically looking at the EPA and saying: “Let’s get real, people in cold states have work to do.”
What the Bill Would Actually Do
The legislation would:
- Require the EPA to update their diesel rules to reflect what cold-weather states actually deal with.
- Grant year-round exemptions from certain DEF requirements for vehicles that primarily operate in frigid regions.
- Reduce the number of stranded-truck scenarios that currently happen because D.C. thinks “winter” means someone turned the AC too high.
In other words: It’s a common-sense fix for places where diesel engines are essential, not optional.
Why Jackson Hole Should Care
Aside from the obvious (we like our trucks to turn on), this matters because:
- Safety: Nobody wants their plow truck shutting down halfway up Teton Pass because a sensor got chilly.
- Economics: Ranchers, tour operators, contractors, and delivery fleets lose time and money when trucks freeze or derate.
- Reality: Jackson Hole runs on diesel. Pretending otherwise is like pretending the runway at JAC isn’t going to close for construction every other year.
This bill recognizes that people in the Mountain West don’t live in a climate where DEF systems get a polite frost; they freeze into DEF-cubes.
Local Commentary (You Knew It Was Coming)
Finally, a federal bill written for people who actually experience winter. Not “my windshield had frost on it once” winter, but real winter. The kind where you plug your truck in at night, pray to the block-heater gods, and wonder why you ever moved here… until you remember how nice the Tetons looked yesterday.
If Lummis and Sullivan succeed, diesel engines will be able to keep working even when the temperature hits the level where your phone battery drops from 100 percent to zero in 14 seconds.
What’s Next
This is just the start. The bill was introduced, and now it’s headed into the legislative obstacle course. But for now, cold-weather drivers in Wyoming have a rare thing, hope.
We’ll keep you updated as this rolls forward ideally with fewer frozen DEF tanks and more trucks behaving like trucks.
Stay warm out there, Wyoming.
AntlersArch founder and the voice behind Teton Tattle.
