The National Park Service on Thursday granted a key permit for the rebuilding of Sperry Chalet.

The project has been moving quickly through the regulatory process. Last month, the Park Service released a draft environmental assessment with four options for rebuilding the chalet that burned last summer in the Spraque Fire. Of these, the “preferred alternative” was restoring the chalet within its original walls, but updated for current safety standards and building codes.

The assessment also discussed possible environmental impacts. After a three-week public comment period, the Park Service has issued a Finding of No Significant Impact, concluding that a more stringent environmental review is not required, and that “the selected alternative will not have a significant effect on the human environment.”

The document acknowledges some impacts from the construction, including: temporary disturbance of vegetation and soil; restrictions on visitor access to the construction site; noise from building and helicopter flights; and adverse impacts to grizzly bears and Canada lynx, both listed as threatened species.

But the finding states that “overall the impacts to wildlife, wildlife habitats, vegetation and soils are anticipated to be small and very localized because the majority of the impacted habitats are of lower quality; they are previously disturbed and within or adjacent to existing development, and are areas of high visitor use (compared to the adjacent area).”

The document also foresees no significant impact to “natural, cultural or scientific resources or public health, public safety, or unique characteristics of the region.”

Several of the comments raised concerns about how the hundreds of helicopter flights needed for the project would impact wildlife, as well as the park’s recommended wilderness areas. Glacier stated that “the Sperry [Environmental Assessment] is considering potential impacts to wilderness character” in accordance with existing policies. It also stressed that the Federal Aviation Administration, not the National Park Service, manages the park’s airspace.

Another comment suggested that the chalet’s future water supply needed more analysis. The document noted chalet managers’ efforts to conserve water in recent years, but said that “any changes to the water system will be explored in future plans and environmental analysis.”

In all, Glacier received 72 comment letters during the review period, 58 of which supported the preferred alternative.

“Today we are one significant step closer in restoring the Sperry experience for the next 100 years of park visitors,” Park Superintendent Jeff Mow stated in a media release Thursday. “We discovered many important design and resource considerations in our conversations with the public throughout the planning process this spring, and look forward to carrying many of them forward.”

Glacier aims to rebuild the chalet in two phases, the first of which will come this summer. The Park Service is currently working with Anderson Hallas Architects to finalize the design, and says it will put construction contracts out to bid this month. Cost estimates are still being prepared, according to park spokesperson Lauren Alley.

To view the Finding of No Significant Impact, visit http://parkplanning.nps.gov/sperrychalet2018.

Reporter Patrick Reilly can be reached at preilly@dailyinterlake.com, or at 758-4407.