Yellow Snowplow at a Mountain Depot

Road salt works by lowering the temperature at which water freezes, which is why plow trucks spread it as they clear. A yellow plow with chains on its tires waits at a mountain depot, the blade still caked with snow. On the very coldest days salt stops helping, so crews switch to sand for grip instead. A snowplow jigsaw puzzle like this doubles as a small thank you to the crews who keep mountain roads open.