Robin Dornfest, PG, CPG

President

Robin specializes in engineering geology and geotechnical engineering as they relate to water and wastewater, oil and gas, transportation, aggregate producers, mining, and water supply and irrigation. Typically, his projects involve geotechnical/geologic investigations, pipeline alignments and crossings, geologic hazard evaluation and mitigation design, small dam design, permanent and temporary earth retention systems, groundwater control, oil and gas pipelines and facilities, highways and bridge construction, commercial and industrial developments, and land development projects. He has technical expertise in engineering geology, geotechnical engineering, slope stability, expansive soils, ground modification, earth retention systems, landslide and rock fall evaluation and mitigation, embankment dam design, groundwater control systems including slurry walls and dewatering well systems, and tunneling and trenchless projects. In addition, Robin has served as an expert witness and provided testimony, evaluated differing site condition claims, and regularly provides value engineering services to numerous client and project types.

Nate Soule, PE, PG

Vice President

Nate has experience in a variety of tunneling, geotechnical, and geological engineering projects. His focus is primarily on tunneling and trenchless engineering and is also constantly involved with more traditional geotechnical projects. Tunneling and trenchless engineering experience includes project management, tunnel design, feasibility analysis, geologic exploration, and contract document preparation. He also assists in plan and specification reviews and litigation support for projects across the country involving both tunnels and other types of construction. Other interests and areas of experience include cementatious grouting and support for hard-rock aggregate quarries.

Benny Siljenberg, PE, MBA

Vice President

Benny’s experience is in a variety of geotechnical, tunneling engineering and construction projects where he has provided benefit to projects for the owners’, contractor’s and prime engineer’s team. His diverse experience allows him to understand a project from all points of view and provide value to each project by considering how individual aspects will affect the overall project. Early in his career his primary focus on design and construction experience with civil structures such as pipelines, water and wastewater treatment plants and reservoirs that is beneficial as he focuses on developing teams, business and pursuits related to the these features.

LANCE HEYER, PE

Associate

Lance is a cofounder and associate of Lithos Engineering.  He has worked on and managed a variety of geotechnical engineering projects and has specific expertise in tunnel and trenchless construction. He has over 5 years of experience analyzing feasibility, designing, and observing and managing construction for tunnel and trenchless projects in Colorado.

Ryan Marsters, PE, PG

Associate

Ryan has experience conducting geotechnical and geologic evaluations for slope stability, geological hazards, abandoned mine subsidence, storm water, environmental compliance, ground water, shallow and deep foundations, roadways, tunnels, dams, pipelines and other civil works.

Ryan’s experience in tunneling, and underground construction includes trenchless design for transportation, water, storm sewer, and sanitary sewer applications. Specific tasks include preparation of Contract Documents, Geotechnical Baseline and Data Report preparation, litigation support and analysis, trenchless feasibility and constructability, tunnel condition assessment, field engineering, and historic tunnel evaluation and rehabilitation. He has served in a variety of roles on tunnel projects throughout the United States involving soft and hard ground and excavation using guided auger bore, guided pipe ram, TBM, MTBM, SEM, hand mining, and drill and blast methods. 

JAMES CARROLL, PE

Associate

Mr. Carroll's experience centers on the tunneling and underground industry, mechanized excavation, ventilation, fire life safety, earth mechanics, alignment selection, condition assessment and rehabilitation. He has contributed to both preliminary and detailed design of tunnels in rock and soft ground, above and below the ground water table. This work has included the planning and implementation of geotechnical investigations to provide for the selection of vertical and horizontal tunnel alignments and the best available excavation means, including conventional drill and blast, mechanized excavation with the use of a Tunnel Boring Machine (TBM) and NATM. Along with tunnel design Mr. Carroll is knowledgeable with the design and construction of deep shafts for construction, future access, ventilation, fire life safety, odor control and drop structures. Mr. Carroll is also certified as a FHWA NHI Tunnel Safety Inspector and NX Burst Safety Cartridges for demolition in sensitive environments.

Matt OLSON, PE

Associate

Matthew Olson is a professional engineer with experience in trenchless construction inspection and management, feasibility studies, preparation and review of contract documents, geotechnical investigations, and cost estimates for trenchless technologies including pilot tube, open shield pipe jacking, pipe ramming, microtunneling, horizontal directional drilling, pipe bursting, CIPP, and auger boring. While attending ASU, he prepared a thesis comparing existing jacking force predictive models to jacking force data he collected while working as a construction laborer on a pilot tube job consisting of over 1,600 lineal feet of gravity pipeline installation. In addition to his academic research experience, Mr. Olson worked as a laborer for Globe Contractors, Inc. during summers for seven years. He has valuable experience working from a consultant and contractor’s perspective regarding installation techniques that maximize workflow efficiencies and minimize project risk for trenchless operations.

Brad Conder, PE

Senior Consultant, Utah Operations Lead

Mr. Conder brings over two decades of experience and local knowledge to lead the company’s Utah operations, focused on building new client relationships in the Salt Lake City region, expanding Lithos’ existing relationships, and providing trenchless consulting uniquely tailored to the needs of Lithos’ Utah partners and their projects. He received both his B.S. and M.S. in Civil Engineering from Utah State University, with an emphasis in geotechnical engineering.  Prior to joining Lithos, he worked for several years in the pipeline rehabilitation industry and has extensive experience in evaluating appropriate trenchless technologies to rehabilitate both gravity and pressure pipelines for sanitary sewer, storm drain and potable water systems.  He also has extensive experience in municipal design and construction, having overseen the preparation of plans and specifications for numerous sewer and water systems and then managing the projects through completion of construction.  Mr. Conder’s background in geotechnical engineering includes slope stability, landslide monitoring and repair, materials testing, construction observation, and geotechnical instrumentation and monitoring.

STEVE KUEHR, PE

Senior Consultant

Mr. Kuehr specializes in geotechnical and tunnel engineering as it relates to water supply, sewerage, water resources, commercial, industrial, highway, bridge and land development projects. He has technical expertise in tunnel engineering, foundation engineering, slope stability, expansive soils, ground modification, retaining walls, landslide evaluation and repair, embankment dam design and groundwater collection trenches and cutoffs constructed by the slurry trench method. He has 40 years of progressive engineering experience involving a wide variety of projects in the disciplines outlined above.   

Dylan Fawaz, PE

Staff Engineer

Dylan is a staff engineer for Lithos Engineering and graduate of Clemson University.  Throughout his career at Lithos Engineering he has become well equipped with experience and technical knowledge that has proven to be valuable on several projects. He has experience in many areas of geological and geotechnical engineering projects including water and wastewater treatment plants, pipelines, tunnels, rockfall mitigation, geotechnical forensic investigation, subsurface investigation, retaining structures, and the production of geotechnical data and engineering reports as well as calculation packages. He is currently pursuing his Master’s Degree in Geotechnical Engineering at Colorado State University.

Derek MAgnuson, PG, CEG

Project Geologist

Derek brings a broad geotechnical consulting background to Lithos as an engineering geologist. He loves a good challenge figuring out what is happening underground for engineered structures. His experience includes 10 years of geotechnical evaluations, geologic hazard assessments, materials testing, construction observation, geotechnical instrumentation and monitoring, and geotechnical forensic evaluations for a variety of projects in Colorado, California, and other western states. He has primarily worked on tunnels, low and high-rise vertical construction, pipelines, roadways, treatment plants, gravel pit reservoirs, and slopes. He also has a background in water quality regulation. Derek graduated from UC Berkeley with a bachelor’s degree in Geology and a master’s degree in Earth Science.

Sarah Myers, EI

Project Engineer

Mrs. Myers holds a B.S. and M.S. in Civil Engineering emphasis in geotechnical engineering and a minor in Geological Sciences from the University of Missouri. Sarah has seven years of experience in tunneling and geotechnical engineering projects. Mrs. Myers has worked on numerous projects with an assortment of responsibilities for private and public owners.

austin wilkes, PE

Staff Engineer

Austin graduated with a bachelor of science in geological engineering from the Colorado School of Mines in May 2015. Austin began working after college with a large consulting engineering firm in Denver, Colorado. Work experience with this firm included underground construction and tunneling, geotechnical investigations, mine reclamation, tailings dam design and construction, water conveyance, and embankment dam design and construction. Over the past 5 years, Austin has gained a proficiency in planning and conducting geotechnical investigations, providing construction oversight, performing geotechnical design calculations, preparing construction drawings and specifications, and developing geotechnical data reports, baseline reports, and design reports. Outside of work, Austin enjoys going to Rockies games, attending concerts across the Denver area, and camping or hiking across the western US.

adam pring, PE

Staff Engineer

Adam graduated with a bachelor’s degree in Geological Engineering and a minor in Underground Construction and Tunneling from Colorado School of Mines in 2015. He continued his education at Mines to earn a master’s degree in Engineering and Technology Management in 2016. Before joining Lithos, Adam worked as a munitions response geophysicist with a large environmental firm. His academic and professional experience include geophysical and geotechnical data collection, data interpretation, and data/engineering analysis. He is also an experienced technical and field team lead. Adam enjoys running, biking and hiking, and has recently taken up fly fishing.

Alexandra warren, EI

Staff Engineer

Alex graduated with a Bachelor’s and Master’s degree in Geological Engineering from the University of Mississippi. Prior to joining Lithos, Alex worked as an interpretation geophysicist for a large technology and service company. Her experience includes geotechnical engineering, engineering geology, geophysical data interpretation, subsurface investigation, and document preparation. In her free time, Alex enjoys hiking, traveling, and playing tennis.

JAMEs HALVERSON, EI

Staff Engineer

James is an experienced engineer, having served in multiple industries including Seismic Exploration, Geotechnical Engineering, Electrical Construction, and Mining Geology. His diverse experience, attention to detail, project & cost management, analysis and management of complex data systems, teamwork, communication, and subsurface analyses are but a few of the assets that James brings to the Lithos team. During his studies at the Colorado School of Mines he worked as a research assistant with the Center of Underground Construction and Tunneling where he helped on several research projects; understanding how joint orientation and other attributes affect cutter wear on the Brennar Base Tunnel Project, understanding how rock composition and orientation affect slope stability, and understanding how the flexural toughness (ASTM C1550) for shotcrete and concrete are affected by various fiber densities and composition, curing times, and primary composition. Mr. Halverson brings excellent leadership skills, the ability to adapt to new and unforeseen situations, and an altruistic perspective to all team and independent project efforts. In his free time, James enjoys spending time with family; road, mountain, and gravel biking; bike packing; weight training; and volunteer work.

Keely Stevenson, EI

Staff Engineer

Keely received a B.S. Degree in Geological Engineering from the Colorado School of Mines in 2021. During her time at Mines, she worked as an undergraduate research assistant on a project modeling flat roofed mine excavations and optimizing rock bolt placement for maximum stability and minimum cost, primarily programming in UDEC. Another project she worked on focused on recycling minerals in mine tailings. In her free time, Keely enjoys hiking, machining, reading, painting, and can be found trying out new things and learning new skills.

Rob Johanson

Staff Engineer

Rob graduated from the Colorado School of Mines with a B.S. in Geological Engineering in 2020 and a M.S. in Geotechnical Engineering in 2021. During his education, Rob worked as a laboratory technician for the Colorado School of Mines Center for Underground conducting soil mechanics laboratory testing for research into Advanced Rapid Tunneling technology. After graduating, Rob gained experience in construction observation and geotechnical investigation at a large Colorado based residential geotechnical firm. While there, he contributed to numerous residential and commercial projects conducting soil compaction testing for sub-excavations, utility trenches, and subgrade using a portable nuclear gauge, as well as observing geotechnical drilling for preliminary geotechnical investigation, foundation design, and forensic geotechnical investigation. Outside of work, Rob enjoys playing the saxophone and piano and making homemade soap and candles.

ADAM MALSAM

Staff Engineer

Adam graduated with a Bachelor’s degree in Geological Engineering from the Colorado School of Mines in 2018. Upon graduating, Adam moved to the east coast to work as a geohazard technical specialist for a leading rockfall mitigation manufacturer and supplier, assisting in the development of rockfall mitigation designs across the USA, Canada, and Caribbean. In 2020, Adam returned to the Colorado School of Mines to pursue a Master’s degree in Geological Engineering, which was completed in 2022. His research consisted of developing an improved understanding of the relationships between weather and rockfall for the Colorado Front Range through analyses of rockfalls identified through lidar and photogrammetric methods. When he’s not working, Adam enjoys spending time outside hiking, fishing, and kayaking. He is also always willing to join a game of pickup soccer or play a round of golf, and is actively trying to improve on the latter.

Kaitlin Reiman

Staff Geologist

Kaitlin is a professionally licensed Geologist with a Bachelor of Science in Geology from Fort Lewis College and a Master of Science in Geology from Stephen F. Austin State University. Kaitlin has a decade of geological experience in a variety of industries that include geologic hazard assessments, environmental remediation, government, higher education and the oil and gas industry. Kaitlin was born and raised in Colorado, and she enjoys travelling, camping, paddle boarding, cross country skiing, hiking, painting and pottery.

OWEN NORWELL

Staff Engineer

Owen received a Bachelor of Science degree in Geological Engineering from the Colorado School of Mines in 2023. During his time at Mines, Owen completed numerous projects featuring field mapping, structural geology, aggregate suitability evaluations, hydrologic evaluations, and geologic hazards and mitigation strategies. Owen's internship experience prior to joining Lithos involved the receiving, processing, and laboratory testing of rock core for an international laboratory. Outside of work, Owen enjoys camping, backpacking, caving, fishing, and playing guitar.

Sissy morphew

Controller

Sissy has 20+ years of professional accounting experience in the engineering industry.  She thrives from working with other employees, problem solving and doing tasks efficiently.  Outside of work, Sissy enjoys spending time with her family, concerts, sporting events and reading.

Adisa HUSEJNOVIC

HR Manager

Adisa is an experienced admin professional, having worked previously at a commercial General Contractor where she managed the bidding process and supported multiple project management teams, in addition to helping an office run smoothly. In her free time, Adisa enjoys being active, practicing photography, and going on roadtrips with her dogs Axel and Toby.