Preserving historical structures is a delicate balance of honoring the past while
ensuring safety and functionality for the future. Tamarack Grove Engineering (TGE)
has undertaken this challenge across several of Idaho’s state parks, providing
meticulous evaluations and innovative solutions for historical preservation. Efforts
at preserving our storied past in Eagle Island State Park, Harriman State Park, and
Bayhorse Ghost Town and Trail System illustrate the significance and complexity of
these challenging – yet significant – projects and why they are so important to save
for the future.
Historic preservation must be conducted in a methodical and consistent approach.
TGE performed the painstaking process of evaluating physical conditions as well as
the quality of materials and the possibility of reuse or salvage. Each parks’ historical
structures posed unique challenges for the TGE team based on current conditions,
materials used, and degree of preservation possible along with budget constraints,
topography, and accessibility.

SAVING HISTORY
Eagle Island State Park, spanning 545 acres, was purchased by the state in 1929 and operated as a prison farm until 1977. It was developed into a park and recreational area by the state in 1983. The park features numerous historic buildings, including a calf barn, dormitory, warden’s house, slaughterhouse, and prison dorm, all constructed between 1930 and 1949. These structures suffered from decades of weather exposure leading to rotting lumber, compromised
structures, and concrete foundation instability. The prison dorm, constructed by inmate labor, had a
partially collapsed roof and insufficient lateral support. TGE designed cross-bracing to preserve the walls while ensuring the building’s stability. Although the interior remains inaccessible to visitors, they can view the unique and historically significant construction techniques used by prison labor in 1949. Another equally important historical evaluation project was the former cattle ranch now known as Harriman State Park, donated to the state in 1977. As an unofficial entrance to Yellowstone, the park covers 11,000 acres at an elevation of 6,120 feet, and features hunting, fishing, hiking, camping, and more. Its remote location and heavy snowfall limit accessibility
for preservation efforts and posed challenges for the team of TGE, contractors, and historical preservation architects, who were scattered throughout the state.
To connect the disparate team member’s locations, TGE established extensive communication protocols between the project experts and Idaho Parks and Recreation department while conducting comprehensive surveys on 33 structures at Harriman as part of Phase I. TGE
assessed overall conditions, as well as foundations, walls, and roofs, sharing the foundational information with the broader team. The resulting report prioritized stabilization or retrofitting needs, setting the stage for the second phase which includes making the buildings sound and accessible.

THE PRICE OF PRESERVATION
Funded by a combination of federal government grants and state funding, TGE was tasked with evaluating and preserving these historical structures within a stringent budget. The TGE team’s approach involved a detailed assessment of each buildings’ conditions and determined which materials, if any, could be salvaged, reused, or repurposed, and provided comprehensive solutions respecting the budget and project goals. While existing materials were assessed for damage and overall condition, it was also imperative to evaluate if they could be removed without damaging them and whether they could be reused or repurposed in any way. Additionally, it was necessary to establish if removal might threaten a building or cause further damage to a structure.
Keeping budgets in mind, TGE delivered cost-effective and inventive solutions for each unique property to preserve as much as possible within the project constraints. For instance, the calf barn at Eagle Island presented a significant challenge. After a thorough evaluation of the columns, walls, overall structure, and the level of deterioration, TGE determined that the roof was in such poor condition that it would require complete replacement. The team then meticulously assessed each exterior siding board and interior wall boards, selecting those that could be reused or
repurposed for the roof replacement and in refurbishing the walls. By maintaining a required percentage of original materials and reusing existing materials for the roof, the barn was restored to a structurally sound state within the allowed budget and respecting the historical significance of the calf barn. These custom measures ensured that the calf barn’s eligibility status for the National Historic Register was maintained.
Cost and existing conditions were major influences on the buildings in the Bayhorse Ghost Town and Trail System located in the Land of the Yankee Fork State Park. The working ranch located in a mining ghost town was listed on the Historic Registry in 1977 but had been abandoned for over 100 years. The site is inaccessible during peak snow periods and the aging timber constructions have suffered from severe weather conditions, leaving them in a dilapidated state.
In 2012, TGE conducted an early evaluation, identifying that the ghost town’s structures had less than two years of life remaining and identified three buildings deemed worthy of preservation.

RE-USE AND RECYCLE
At every step along the way, TGE respected the historic record told by each building in the Idaho state parks system and turned a practiced eye toward evaluating existing materials on all the structures and assessing board by board and brick by brick what could be salvaged and reused. Materials that were not reusable were slated to be remade with salvaged materials or identified for alternate uses. Per historic guidelines, the team maintained the required percentage of original
materials, even if those materials were repurposed on site, maintaining historical integrity. Every material removed or dismantled was meticulously numbered, logged, and assessed.
TGE’s attention to detail and passion play a leading role in protecting significant structures and helps highlight the benefits of historic preservation which include:
Cultural Heritage
Preserving structures maintains a tangible connection to Idaho’s history, allowing future generations to experience and learn from the past.
Educational Value
Restored buildings serve as educational tools, providing insights into historical construction techniques and the lives of people from different eras.
Tourism
Well-preserved historical sites attract tourists, boosting local economies and fostering community pride.

TGE’s projects in Idaho’s state parks exemplifies the challenges and rewards of historical preservation. Through meticulous evaluation and innovative solutions, they ensure these significant structures are preserved for future generations. The projects at Eagle Island, Harriman, and Bayhorse Ghost Town highlight the importance of preserving our cultural heritage while balancing modern safety and accessibility requirements.
For more information on Tamarack Grove’s work on historic structures, please contact Doug Hardin, PE and Will Workman, PE.
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