The Spring Plowing of Trail Ridge Road

Each spring a crew works from both ends of Rocky Mountain National Park's highest paved road, cutting through drifts until the gates open.

Abe Lindgren 4 min read

The spring plowing of Trail Ridge Road is done by the road crew of Rocky Mountain National Park, working from both ends toward the middle. The road is the highest continuous paved road in the United States, and it closes with the first heavy snow of autumn; by the time the crew comes back to it, the drifts have buried the guardrails and only the tops of the tall roadside markers show, each one a post with a reflector that the plow drivers steer by.

The staging

The crew starts at the maintenance shop, where the rotary plows have sat all winter. A rotary plow is a heavy truck with a spinning auger and a fan mounted on the front. It bites into the snow, chews it, and throws it out in a long white stream from the discharge chute. The crew checks the auger teeth, the hydraulics, the belts, the undercarriage, and the heaters in the cab, because the work is done in wind and below-freezing air. The graders are checked the same way, and the snowmobiles are loaded on trailers. The machines drive up the closed road as far as the bare pavement goes, and the trailers stop at the gates, one on the east side and one on the west. The plow blades rest on the dry pavement, and the snow stands in a wall at the gate.

A snow-covered peak in Rocky Mountain National Park above a dark band of forest in June

Reading the snowpack

Before the plows move, the crew goes up on snowmobiles. They ride the buried road by the markers, stopping to probe the snow with long rods to see how deep it is and what lies underneath — rocks and timber from winter slides sit on the pavement in places. They check the crossings and the stretches of road that run under a slope, and they look up at the cornices hanging off the ridgelines. A missed marker is the difference between the road and the fall-off, so the line is walked post by post. The crew comes back down with the route mapped, and the markers stand over the snow in a line the drivers can follow.

The avalanche check

No plow works a slope that is loaded. The crew reads the snowpack and the forecasts, and the slopes above the road are watched as the sun strengthens. Some slopes the crew waits out until the afternoon warmth brings them down, and when a slope runs the sound arrives first — a crack, then a deep push of air — and the crew stops and watches the white cloud roll across the road. Other slopes are brought down on purpose before the plow sits under them. When the debris lies still across the road and no more snow moves overhead, the plow idles forward under the slope.

The first cut

The rotary plow goes first, into the deepest drifts. It cuts a slot just wider than the truck, moving at walking speed, and the snow leaves the chute in a stream that spreads on the wind and lands far down the slope. The snow in the cut is wind-packed and dense, and it comes out in chunks as often as powder. The driver steers by the tops of the markers, because the road is invisible — the blade is carving through snow that stands taller than the cab. The plow reverses and makes another pass, and another, each one widening the slot by a blade's width. What is left behind is a trench with straight sides of blue snow.

A snow cornice over a cliff edge along Trail Ridge Road

Widening the cut

The graders follow the rotary. The blade pushes the cut snow off the road and over the fall line, widening the slot until there is room for two vehicles to pass. In the shade the snow has packed to ice, and the blade edge is dropped and run against it, peeling it off in slabs. The pavement appears in patches, then in long runs, wet and dark against the white. The road runs full width, and the snow walls stand set back on both sides.

Down to the pavement

The final scraping pass strips the road down to the asphalt. The grader blade is set low, and the last packed ice is cut away. Winter has heaved the pavement — there are broken edges and potholes where frost has lifted it — and the crew marks the worst sections with paint for the repair crew. The culverts are dug out by hand, each opening shoveled clear so the meltwater has a place to go instead of crossing the road. The guardrails are uncovered and pulled back into line where the snow has bent them.

The opening

The two crews meet on the tundra, high on the road, where the east-side and west-side cuts come together. The last work is the push-out — the parking lots and pullouts are cleared, the snow shoved off the pavement and over the edge of the drop. The barricades are lifted and the gates are swung open against the banks. Trail Ridge Road runs open from gate to gate, and the snow stands in blue walls on both sides of the pavement.