No Structures Too Far for NPS Wildland Firefighters

By Brian Sorbel

NPS wildland fire management staff complete a wildland fire risk assessment of the New Birch Creek Cabin in Denali National Park and Preserve.

NPS photo

In July 2016, wildland firefighters from the NPS Alaska Western Area Fire Management Program visited the New Birch Creek Cabin in the remote backcountry of Denali National Park and Preserve. The purpose of this site visit was to complete a structure wildland fire risk assessment of the cabin and surrounding outbuildings in order to help gauge the risk wildland fire poses to these structures.

Risk assessments of structures is a common practice in wildland fire. In 2011, an effort was launched to assess wildland fire risk to NPS structures nationwide with the goal of eventually completing risk assessments on 90% of NPS structures. By 2019, 90%, or approximately 30,000 NPS structures had been surveyed.

To finish the risk assessment at the New Birch Creek Cabin, NPS personnel entered information about the structure and nearby fuels (burnable vegetation) onto a field data form and collected digital photos of the structure and surrounding area. For example, inputs were completed relating to means of access, nearby water sources, presence of propane tanks and/or firewood, topography and fuel loading. Inputs to these and other criteria generated a final wildland fire risk score and rating. The information collected indicated that the New Birch Creek Cabin was at high risk from wildland fire. In addition to contributing to the nationwide effort, it was recognized that the information collected about these structures could be used for fuel treatment planning as well as structure protection planning in the event of a wildland fire in the area. Fuel treatments may involve thinning out burnable vegetation or utilizing prescribed fire to help reduce the amount and continuity of fuel in an area. In this case, it gives the structure greater defensible space between its walls and future flames. Natural and cultural resources sites, like the New Birch Creek Cabin, have the potential to complicate protection efforts for wildland firefighters. Having a plan on how to protect structures, like wrapping, plumbing, and available resources, plays a role in determining if structures will remain standing during and after a wildfire.

Map of Foraker Fire perimeter and locations of nearby New Birch Creek and Collins Slippery Creek cabins.

Fast-forward three years later to the summer of 2019…
An actively burning wildfire discovered on the afternoon of June 26 threatened the New Birch Creek Cabin. The fire was a little over four miles to the east of the cabin. At the time of discovery, the lightning-caused Foraker Fire had already burned over 100 acres. Due to the fire’s location and natural cause, the fire was managed primarily through surveillance and monitoring with structure protection measures put in place at the New Birch Creek Cabin and other cabins near the fire. Firefighters would eventually burn out around the New Birch Creek cabin in order to protect it from the Foraker Fire, which would eventually grow to 49,527 acres and get within 1/3 of a mile of the New Birch Creek Cabin.

Fire management online mapping application showing the location of fire perimeters (blue outline) and NPS structure risk assessments in Yukon-Charley Rivers National Preserve during the 2019 fire season.

For the duration of the Foraker Fire, as well as throughout the record-setting 2019 Alaska fire season, NPS structure risk assessment data proved useful for developing plans to protect structures and as a data layer in strategic decision support planning tools used in the management of several large NPS fires. Data, including photos, from the structure risk assessments were available to fire managers during the fire season through a variety of online mapping sources as well as in hardcopy report formats.

The NPS manages approximately 52.5 million acres in Alaska across 24 different NPS units. While much of the NPS land in Alaska is remote and unpopulated, there are nearly 4,000 individual structures spread throughout the parks and preserves in Alaska. Of that total, 2,756 are NPS structures. These structures can range from large groups of road-accessible buildings in headquarters areas to remote backcountry cabins accessible only by aircraft. While 43% of NPS structures in Alaska are within one mile of a road, the majority are more than one mile from a road and generally only accessible by air or, in some cases, watercraft. In contrast, 95% of NPS structures in the contiguous United States are accessible by road. For the 1,548 NPS structures in Alaska that are further than one mile from a road, the average distance from the structure to the nearest road is 32 miles! Frequently, the hardest part about completing a risk assessment of a structure in an Alaska park is just getting to the structure.

Despite these challenges, the NPS has made significant progress towards the goal of completing risk assessments for 90% of NPS structures in Alaska using a multipronged approach. Combining on-the-ground site visits wherever possible along with risk assessments completed remotely using GIS data, aerial photography and satellite imagery as well as photographs and reports increased strides toward success. To date, the NPS has completed wildland fire risk assessments on 80% of NPS structures in Alaska contributing to an overall accomplishment of 93% of NPS structures nationwide being surveyed. In coming field seasons, the NPS will continue to work towards completing additional structure risk assessments in order to bolster the capabilities of this valuable fire and fuels management planning tool.