Great FallsGeolocation: 47.4908, -111.3376

The Great Falls office was formed in 1991 as NTL Engineering & Geoscience, Inc., an employee-owned Montana corporation practicing in the geotechnical, construction materials, and environmental engineering and testing fields. NTL joined Terracon in 2008 and officially changed its name to Terracon in 2013. The Great Falls engineering staff have a wide range of geotechnical experience on projects ranging from large industrial facilities to dams, bridges, highways, landslides, rockfalls, retaining structures, defense facilities, and seismic-related studies with geographic project involvement ranging from Wyoming to Alaska. We provide construction materials engineering/testing and QA/QC services for projects ranging from buildings and pavements to earth structures. In-house testing services include determination of soil/aggregate index and engineering properties, Portland and asphaltic cement concrete mix designs and related testing, along with field quality control services during construction.  

1392 13th Ave.SW
Great Falls, MT 59404

Phone: (406) 453 5400
Fax: (406) 761 6655




Matthew Hoffmann, Office Manager

Key Projects

Flathead County LandfillGeolocation: 48.4242, -114.1532

This project presents the results of Construction Quality Assurance (CQA) services provided by NTL

Engineering & Geoscience, A Terracon Company, during construction activities associated with the Phase IV-A excavation and final closure of the north and east slope construction project at the Flathead County Sanitary Landfill in Flathead County, Mont. The purpose of the closure is to provide a barrier on the slopes of the landfill that have attained final elevation. The two slopes closed for this project encompassed an area of approximately 14 acres. The final cover/barrier was…

Flint Creek LandslideGeolocation: 46.3375, -113.4648

This first phase of this project included evaluation of landsliding and rock sliding along 5 km of high-hazard rockfall zones along Montana Route 1 in Granite County, MT. Terracon personnel performed geologic, geotechnical, and photogeologic mapping of rock outcrops along the project. In the second project phase, Terracon was retained by Montana DOT to perform observations and testing of rock bolt/rock nail and debris flow structure installation. Using high-angle climbing techniques, Terracon personnel designed and implemented a testing equipment restraint system and then observed the…

Great Falls International Airport, Runway and Parallel TaxiwayGeolocation: 47.5002, -111.3008
After providing geotechnical engineering support for design of the projects, NTL, A Terracon Company, provided both Quality Assurance (QA) and Quality Control (QC) materials engineering and testing for reconstruction of Runway 3/21 and Taxiway A at the Great Falls International Airport. The project included evaluation of soils/bedrock used as subgrade and substantial grade raising. Construction control and assurance included earthwork compaction, along with new Portland cement concrete and asphalt paving materials testing on the main runway and connecting taxiways. Due to the compressed…

Kalispell Bypass – US Highway 93 AlternateGeolocation: 48.2005, -114.3151
NTL Engineering & Geoscience, A Terracon Company, performed the geotechnical investigation for the Kalispell Bypass. Our involvement began in 1995 with a preliminary soil survey and culminated in 2010 with construction of the southern half of the alignment. Along with providing pavement section design recommendations for the Bypass Mainline and 20 associated named roadways, geotechnical guidance was provided for noise walls, pedestrian tunnel, and 10 bridge structures for creek crossings and separated-grade intersections. Challenging subgrade conditions were present along much of the…

PPL Madison DamGeolocation: 46.8797, -110.3626
NTL, A Terracon Company, provided geotechnical design and construction observation services for the rock slope stabilization at the PPL Madison Dam in southwest Montana. Rockfall had damaged the dam's left abutment, and a program of rock bolting to stabilize large gneiss blocks was undertaken in conjunction with installation of a Geobrugg rockfall system of ring nets and high-strength wire mesh to provide both construction safety and long-term protection

Sam Bibler Memorial TrailGeolocation: 48.2005, -114.3151
The Sam Bibler Memorial Trail in Kalispell, Mont., included a section of the bicycle/pedestrian path that was constructed on a relatively steep embankment, which exhibited signs of adverse slope performance prior to construction. NTL Engineering & Geoscience, A Terracon Company, performed the geotechnical investigation for the retaining feature that would allow for grade raising without negative impact to the roadway embankment. Though traditional retaining features were reviewed, the project team elected to use an innovative approach using ultra-lightweight fill (geofoam) with…