Geologic Mapping Program

The Geologic Mapping Program maps Utah’s geology at scales of 1:24,000 (7.5-minute quadrangle maps) to 1:100,000 (regional maps). These maps and accompanying materials depict and interpret the composition, age, and depositional environment of exposed and subsurface rocks; geologic structures such as faults and folds; Quaternary (surficial) cover; geologic hazards such as landslides and earthquake-producing faults; and economic and groundwater resource features. The maps are used by geologists, government officials, industry representatives, university professors and students, and the public to better understand Utah’s geology, delineate and interpret the economic value and potential of property, assess geologic hazards, and make land management decisions.

Geologic Map Uses

  • Land-Use Planning – Roads and transportation, critical facilities, civil engineering, underground storage facilities, water treatment and delivery, energy facilities, protecting sensitive ecosystems
  • Geologic Hazards Evaluation – Earthquake research, landslides, volcanic hazards, flooding, karst and clays, human-induced geohazards, human health hazards
  • Water Resources – Groundwater development and protection, water injection/withdrawl, water pollution, dam/reservoir/canal construction sites
  • Recreational Resources – Selection and siting of parks and recreational areas, preservation of unique geologic sites
  • Energy Resources – Oil and natural gas, coal, radioactive materials, renewable resources
  • Mineral Resources – Metallic minerals, chemicals and fertilizers, industrial minerals, construction materials, rare earth elements
  • Waste Disposal – Landfill facility siting, toxic and nuclear waste disposal, sewage collection and treatment, underground facilities
  • National Defense – Strategic minerals, military testing and training facilities, safe weapons repositories, underground command facilities, space port facilities, FEMA facilities siting


  • 30 x 60-Minute Quadrangles at 1:62,500 to 1:100,000 (Intermediate) Scales – The primary regional goal is to complete all 46 Utah 30 x 60-minute quadrangles at 1:62,500 to 1:100,000 (intermediate) scales and produce printed, online, and geographic information system (GIS) products that meet the needs of map users.  The maps are created from new field mapping and older quality maps.  Currently, about 75% of the state is completed.
  • 7.5-Minute Quadrangles at 1:24,000 Scale – The primary detailed goal is to map all 1512 Utah 7.5-minute quadrangles at 1:24,000 scale.  Priorities for mapping are set by a State Mapping Advisory Committee and are based on rapid urban growth, large geologic hazard potential, high geologic resource potential, and high recreational use.  The maps provide more detail and spatial accuracy than the regional maps but cover much smaller areas and take much more time to complete.   Currently, about half the state is completed to a minimal level; about 10% is completed to a maximum level.
  • Structural and Historical Geologic Mapping – The Mapping Program also researches and provides impartial expertise on Utah’s geologic features (such as landforms), rocks, geologic history, geologic nomenclature, and geologic structures.

Geologic Mapping Staff

Geologic Manager

Stefan Kirby

Phone: (801) 537-3349
Email: stefankirby@utah.gov

Stefan Kirby is the Geologic Mapping Program Manager. He is a licensed Professional Geologist with a diverse background in field geology and interpretive science. He has authored and co-authored numerous 1:24,000- and 1:100,000-scale geologic maps across Utah. His work also includes a broad range of topics such as geothermal projects, basin-scale groundwater studies and water budgets, local and regional geologic mapping in the eastern Great Basin, establishment of regional-scale groundwater level and groundwater quality monitoring networks, statistical analysis of basin-scale groundwater chemistry, aquifer testing, and drilling and completion of various types of groundwater monitoring wells. Stefan received a M.S. in geology from Utah State University in 2005 and joined the UGS 2004.

Project Geologist

Zach Anderson

Phone: (801) 538-4779
Email: zanderson@utah.gov

Zach earned his B.S. and M.S. in geology from Northern Arizona University. His Masters work focused on Miocene structure, stratigraphy, and tectonics of the Lake Mead area, Nevada. Zach worked with the USGS’s geologic mapping program in Flagstaff, Arizona, for seven years, mainly doing structural research and geologic mapping along the lower Colorado River corridor. Zach joined the Utah Geological Survey’s mapping program in 2013 as a GIS analyst. In 2016, Zach started as a mapping geologist for the Utah Geological Survey. He is currently mapping 7.5′ quadrangles in the Wasatch Front and Wasatch back valleys.

GIS Analyst

Kaitlyn Bocik

Email: kbocik@utah.gov

Kaitlyn Bocik is a GIS analyst with the Utah Geological Survey. She was born and raised in east Tennessee and has always had a love for nature and the mountains of southern appalachia. She graduated from the University of Tennessee with a degree in environmental sustainability and geospatial science. Since then, she has worked on various research projects ranging from forest ecology to lidar technology. The last couple of years she has worked with the National Park Service as a cartographic technician managing data and online mapping programs. She is excited to make maps and learn more about Utah’s geology through geography!

Geologist (Hydrogeology)

Hector Zamora

Phone: (915) 873-8769
Email: hzamora@utah.gov

Senior Scientist

Don Clark

Phone: (801) 537-3344
Email: donclark@utah.gov

Don Clark is a Senior Scientist with the Utah Geological Survey’s Geologic Mapping Program. He conducted mapping initially as a student and later as a contract and in-house mapper at the UGS. Projects involved preparation of intermediate- and detailed-scale quadrangle maps and associated data reports in the eastern Basin and Range Province of northwestern and central Utah. Don has collaborated with scientists at the UGS, the U.S. Geological Survey, universities, and private entities.

Senior GIS Analyst & Cartographer

Rosemary Fasselin

Phone: (801) 537-3351
Email: rfasselin@utah.gov

Rosemary Fasselin has kept herself busy for the last 15 years as a GIS professional analyzing spatial data, developing field apps, managing projects, training others, and coordinating GIS programs. Born and raised in Utah, she has always loved her home state’s geology and is thrilled to be a part of mapping it! Rosemary earned a B.A. in english and a GIS Certificate from the University of Utah in 2008; she earned a Master of Natural Resources and a second GIS Certificate from Oregon State University in 2020. Rosemary joined the Utah Geological Survey in 2019 where she is currently developing a process to make all GIS mapping data compliant with the USGS Geologic Map Schema (GeMS). When she’s not doing GIS, you’ll find Rosemary camping in remote parts of Utah, observing nature in her backyard as closely as she can, and generally loving life with her husband and their tripawd pittie, Hope.

GIS Analyst

Keilee Higgs

Email: keileeann@utah.gov

Keilee Higgs is a GIS geological technician with the Geologic Mapping Program and currently leads the archiving processes for the map bibliography data preservation program (MapBib). She earned a B.S. degree in geology in 2020 and a geospatial analysis certificate in 2021 from Weber State University. Along with her data preservation work, Keilee helps out wherever she is needed in the mapping program, including working on converting UGS maps to qualify for the U.S. Geological Survey’s Geologic Map Schema (GeMS), digitizing maps for use in the field and for publication, and georeferencing and standardizing of map data.


Jon King

Phone: (801) 537-3354
Email: jonking@utah.gov

Jon joined the Utah Geological Survey in 1992 and is a Senior Geologist in the Geologic Mapping Program. He is a co-author on the Ogden 30 x 60-minute geologic quadrangle map, 14 detailed geologic maps within the quadrangle, and 2 detailed geologic maps adjacent to the quadrangle. He plans to co-author and complete four detailed geologic maps in Cache Valley before he retires. Prior to 1992, Jon worked for the Wyoming State Geological Survey for 7 years investigating industrial minerals, construction materials, uranium, thorium, rare earth elements, and gold (everything from abrasives to zeolites) and generating about 30 publications. His first real job in geology was in 1976 finishing the landforms map of Sheridan County, Wyoming, for the then Geological Survey of Wyoming.

Senior GIS Analyst

Basia Matyjasik

Phone: (801) 537-3122
Email: basiamatyjasik@utah.gov

Basia Matyjasik is a Senior GIS Analyst in the Geologic Mapping Program at the Utah Geological Survey.  She joined the UGS in 1998 and has completed GIS work on dozens of intermediate- and large-scale geologic maps that cover a large part of the state. She graduated with a M.S. degree in geology from University of Warsaw in 1987 and is a licensed Professional Geologist in the state of Utah.

Wetland Technician

Grant Mauk

Email: grantmauk@utah.gov

GIS Analyst

Subigya Shah

Email: subigyas@utah.gov

Senior Scientist

Grant Willis

Phone: (801) 537-3355
Email: grantwillis@utah.gov

Grant Willis has worked for the Utah Geological Survey’s Geologic Mapping Program his entire career which encompasses 12 years as a field geologist and 27 years as Program Manager. He has been a part of the Mapping Program from its formation in 1983, and has led it through many changes, including the transition from building maps using mylar, rapidograph drafting pens, scribe coat, and bluelines, to digital photogrammetry and GIS databases. He has overseen the review, production, and publication of hundreds of geologic maps, and has been lead or co-author on over 40 maps. He developed field safety policies and manuals for the UGS and served on the Department of Natural Resources Vehicle Accident Safety Committee and the state Geographic Names Committee for 15 years. He has also served in many roles in the professional community, including as president of the Utah Geological Association (UGA) and as chair of the UGA Earthquake Safety Committee, where he wrote and created a website devoted to the earthquake dangers of unreinforced masonry buildings. He recently stepped down as Program Manager to spend his last couple of years with the UGS as a field mapper.