In June 2022, Yellowstone National Park experienced its most catastrophic flooding event in recorded history. Unprecedented rainfall combined with rapid snowmelt caused the Yellowstone River and its tributaries to overflow, washing out bridges, severing roadways, and isolating entire communities within the park. Vital transportation corridors were either underwater or destroyed, prompting the National Park Service to act swiftly to restore safe access for residents, visitors, and emergency services.
One of the most critical needs was establishing a reliable bypass route into the park’s Mammoth Hot Springs area after the primary access road was rendered impassable. GeoStabilization International (GSI) was contracted on an emergency design-build basis to stabilize slopes along the Old Gardiner Road, a historic route reactivated to serve as a temporary but essential artery for park operations and tourism.
The terrain along the Old Gardiner Road presented immediate geohazard risks, with steep, eroded slopes threatening both road integrity and traveler safety. Without intervention, these slopes risked failure under the increased stress of construction activity and subsequent traffic loads.
GeoStabilization’s solution involved installing over 20,000 square feet of soil nails paired with high-tension TECCO® Green mesh to reinforce the slope and protect against future movement. The soil nails, drilled deep into the slope, provided critical anchorage, while the TECCO® mesh secured surface soils and vegetation, integrating visually with the natural environment to minimize aesthetic impacts within the National Park.
Given the lack of site-specific geotechnical data, GSI’s engineers relied on back analysis of existing conditions and field-verified testing to optimize the design in real-time. This adaptive approach ensured the stabilization measures were both effective and cost-efficient despite the urgency and complexity of the project.
Through close collaboration with the National Park Service and general contractors, GeoStabilization delivered a durable stabilization solution that enabled the Old Gardiner Road Bypass to reopen safely and remain operational throughout ongoing park recovery efforts. This project exemplified GSI’s ability to provide rapid, reliable geohazard mitigation under extreme circumstances, preserving essential access for Yellowstone’s communities and visitors.
