Images

The bark at the base of a tree in a burned watershed in the 2024 Ek Fire burn area has been partially removed by fast-moving water and debris. This damage occurs as debris flows pass through the channel and sediment suspended in the flow scrapes bark off of trees.

Runoff during a 2025 summer thunderstorm carried material downstream in this relatively small channel in the High Water Creek watershed within the Elk Fire burn area.

Runoff in the 2024 Elk Fire burn area. This meadow near a watershed outlet along Lower Dry Fork Road shows a shallow channel formed during Summer 2025. Although vegetation is recovering, runoff deposited mud and flattened grasses in this low-slope area.

Sediment transported by storm runoff was deposited in this small channel draining from Dry Fork Ridge in the Elk Fire burn area. The deposit includes a mix of woody debris, gravel, cobbles, and finer material typical of flood or debris-flow processes.

Postfire debris-flow deposit in a channel within the 2024 Elk Fire burn area near Dayton, Wyoming. Following a July 2025 thunderstorm, the channel filled with mud, cobbles, small boulders, and woody debris. This photo, taken near the watershed outlet, looks upslope from U.S. Highway 14.

Burned trees and loose material cover a burned hillslope in 2024 Elk Fire burn area near Dayton, Wyoming. Rills, in the foreground formed from rainfall running off the ground surface. New green vegetation shows early signs of postfire recovery.

Woody debris forms an upstream dam in the 2024 Elk Fire burn area near Dayton, Wyoming. The dam was deposited by a debris flow triggered during a 2025 summer thunderstorm. The woody debris forming the dam is larger and more abundant than material observed lower in the channel.

Knickpoint (a step-like feature in bedrock along stream channel) near the headwaters of a burned watershed in the 2024 Elk Fire burn area near Dayton, Wyoming. The exposed bedrock is heavily fractured, and loose material is visible at the base. During storms, this material can be mobilized and transported downstream.

Close-up view of a debris-flow deposit in the 2024 Elk Fire burn area near Dayton, Wyoming. A debris flow triggered by a 2025 summer thunderstorm deposited poorly sorted material ranging from mud to boulder size. Mud coatings are observed on some larger rocks, and finer material fills spaces between the cobbles and boulders.

Channel in a burned watershed within the 2024 Elk Fire burn area near Dayton, Wyoming where a debris flow initiated during a July 2025 thunderstorm. Near the headwaters, exposed bedrock is visible in channel, and loose sediment and burned trees cover the hillslope above. Trees near the channel margin show damage from the force of the flow.

Postfire debris-flow levee in the 2024 Elk fire burn area near Dayton, Wyoming. This levee, located near the channel margin contains poorly sorted sediment ranging from fine mud-to boulder-sized. A small amount of woody material is also present in the levee. The levee was formed by a debris flow in the watershed, triggered by a 2025 summer thunderstorm.

Burned watershed in the 2024 Elk Fire burn area where a debris flow was triggered during a July 2025 thunderstorm. This downstream view shows the watershed outlet near the Crystal Springs Rest Area and U.S. Highway 14. Heavy equipment used to clear the debris remains on site 8 days after the event.

Debris-flow deposit in the 2024 Elk Fire burn area. The flow partially covered U.S. Highway 14 west of Dayton, Wyoming. Sediment and woody debris partially covered U.S. Highway 14, near the Crystals Springs Rest Area after a thunderstorm triggered a debris flow in a burned watershed.

Postfire debris-flow deposit in a channel within the 2024 Elk Fire burn area near Dayton, Wyoming. Following a July 2025 thunderstorm, the channel filled with mud, cobbles, small boulders, and woody debris. This photo, taken near the watershed outlet, looks upslope from U.S. Highway 14.

USGS Postfire landslide monitoring station in the 2024 Elk Fire burn area near Dayton, Wyoming. The station records rainfall and soil moisture data and captured video of a debris flow on July 15, 2025. The channel where the flow occurred is visible in the background.

Postfire debris-flow deposit in the 2024 Elk Fire burn area near Dayton, Wyoming. A debris flow triggered by a July 2025 thunderstorm deposited sediment and woody debris within the channel. Downed trees, oriented perpendicular to the channel banks, form a wood dam.

Postfire debris-flow deposit in a channel within the 2024 Elk Fire burn area near Dayton, Wyoming. Following a July 2025 thunderstorm, the channel filled with mud, cobbles, small boulders, and woody debris. The material shown here is finer than deposits near the watershed outlet. Several trees in the channel show evidence of damage from the debris flow.

USGS scientists install a postfire monitoring station in the Elk Fire burn area near Dayton, Wyoming. Installed less than a year after the wildfire, the station records hydrologic responses during rainfall on the burned landscape.

USGS postfire monitoring station in the Elk Fire burn area near Dayton, Wyoming. Installed less than a year after the wildfire, the station records hydrologic responses during rainfall on the burned landscape. Located above a channel that was assessed to have a very high likelihood of debris flows, it collects data on soil properties and rainfall.

Crystal springs watershed in the 2024 Elk fire burn area.  The USGS installed a monitoring station here to record postfire hydrologic responses during rainfall events.  This photo was taken before any flooding or debris flows occurred, but the station later recorded a debris flow during a July 2025 thunderstorm.  

A USGS hydrologist checks a newly installed rain gage in the Elk Fire burn area near Dayton, Wyoming to ensure that it is level. USGS scientists installed several rain gages throughout the Elk Fire burn area. Rain gage data is paired with observations of flooding and debris-flows to test how well the USGS hazard assessment models are working.