August 13, 2022

Badwater Road runs south from Furnace Creek and provides access to some of the most iconic spots in Death Valley National Park, including Badwater, Artists Drive, Natural Bridge Canyon, and Devils Golf Course. The road, narrow two-lane blacktop, runs south from Highway 190 at the mouth of Furnace Creek Wash, hugging the faulted western base of the Black Mountains for a few miles before running in straight stretches across alluvial fans. Approaching Badwater the road is forced back to the steep mountain front to avoid crossing the muddy salt flats.

Death Valley, Badwater Road, Ventifact Ridge — Badwater Road heading south across alluvial fans toward Artists Drive and Ventifact Ridge

Diversion of Furnace Creek Wash down Gower Gulch 80 years ago has caused a lot of grief for the people who maintain the Park’s roads. Before the diversion, Gower Gulch, like better-known Golden Canyon half a mile to its north, drained a small (two square mile) area of soft sedimentary and minor volcanic rocks in the northern Black Mountains. It has been slowly eating eastward, and before the artificial diversion there was only a low drainage divide of soft siltstone separating it from Furnace Creek Wash. That system drains an area about 100 times larger than that drained by Gower Gulch, and carries much larger and harder rocks derived from the Funeral Mountains.

The consequences of sending floods from Furnace Creek down poor little Gower Gulch were predictable and dramatic. Gower had built a small alluvial fan of relatively fine-grained sand, pebbles, and cobbles at its faulted mouth, and the system was reasonably stable and content. Heavy rains would send small debris flows down the little fan, but these typically spread out and dissipated before reaching Badwater Road. The first post-diversion floods from Furnace Creek, however, deranged the system. They were much larger than pre-diversion floods and far more erosive owing to the much greater volume of water and the much larger and harder tools (rocks) that they carried. They quickly carved a deep trench into the head of the old fan, and this trench confined subsequent flows, allowing them to flow farther down the fan.

Badwater Road at Gower Gulch looking north toward Golden Canyon and Furnace Creek. This part of the road is typically buried by flood debris washed down Gower Gulch during storms, and the bulldozed material on the left is debris from the last time the road was cleared.

About a quarter-mile from the range front, shortly before reaching the road, the new channel has been depositing material rather than eroding into the old fan. Every significant storm deposits debris on the road and rips up asphalt, which has been reinforced by various means over the years. The road is essentially being periodically buried under a new, larger fan that really wants to bury the road for good.

Flood debris from Gower Gulch across Badwater Road in 2017. Photo courtesy of Garry Hayes, geotripper.blogspot.com

If anyone has a good idea on how to fix this, tell the Park Service.

Parking along Badwater Road and walking up to the range front is an easy walk and an interesting lesson in geology. Within 100 yards of the road the channel that has carried the road-burying material down the gulch becomes incised—just a few feet at first, but rising to fully 20 feet at the mouth of the canyon. The material exposed in the vertical walls of the eroded fan is relatively fine-grained, locally derived material from the local drainage—clasts of sedimentary and volcanic rocks of the Furnace Creek Formation. The stuff in the bottom of the wash is quite different—much larger clasts of limestone, dolostone, and other rock types that are exotic to the local area and were carried in from the Funeral Range by Furnace Creek Wash.

OK, this may not be a spectacular photo, but it tells an interesting story. The vertical wall, carved in the old, pre-diversion fan, consists of young volcanic and sedimentary material from Gower Gulch proper. The much larger rocks littering the bottom of the active wash are exotic to the area and were carried down Furnace Creek Wash and then down little Gower Gulch. The larger floods that carried them were quite effective at cutting down into the old, soft fan. Twenty feet and counting.

You don’t have to look very hard to find even more exotic material—asphalt from Highway 190, which is periodically ripped up at the diversion site by headward erosion of the newly emboldened Gower Gulch.