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

Grant Willis

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

Grant Willis has worked for the Utah Geologic Survey’s Geologic Mapping Program his entire career which encompasses 12 years as a field geologist and 24 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 has developed field safety policies and manuals for the UGS and has served on the Department of Natural Resources Vehicle Accident Safety Committee for 15 years 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.


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.


Bob Biek

Phone: (801) 537-3356
Email: bobbiek@utah.gov

Bob Biek is a Senior Scientist with the Utah Geological Survey’s Geologic Mapping Program, having joined the group in 1996 after 4 years as a mapping geologist with the North Dakota Geological Survey. Most of his geologic mapping is in southwestern Utah and along the Wasatch Front. He is lead author or co-author of nearly 40 7.5-minute geologic maps, and he is lead author of the St. George and Panguitch 30 x 60-minute quadrangle maps and is wrapping up the west half of the Loa 30 x 60-minute quadrangle. Bob received a B.A. in Geology from the University of California at Berkeley in 1983 and a M.S. in Geology from Northern Illinois University in 1987.

In 2014, while working to map the Panguitch 30 x 60-minute quadrangle with colleagues Peter Rowley (Geologic Mapping Inc.) and David Hacker (Kent State University), they discovered the gigantic Markagunt gravity slide, one of the largest terrestrial landslides on earth. In 2016, while working to map the Loa 30 x 60-minute quadrangle, they discovered the adjacent, slightly older but also gigantic Sevier gravity slide. And in 2017, they convened an international field symposium, bringing together experts from around the world to evaluate these discoveries “on the outcrop.” New, multidisciplinary research is now underway to better understand the extent, age, and emplacement mechanics of these extraordinary landslides.

Senior GIS Analyst

Kent Brown

Phone: (801) 537-3350
Email: kentbrown@utah.gov

Kent Brown is a Senior GIS analyst and photogrammetrist with the UGS Geologic Mapping and Paleontology Program and has been instrumental in the development of the program’s geologic map publication methods. He joined the UGS in 1983 and served as Senior Cartographer in the Editorial Services Section before transferring to the Geologic Mapping Program in 1990 to manage a newly acquired photogrammetry system. Since 2002, he has utilized up-to-date digital photogrammetry methods and has developed a statewide collection of 3D stereo models, as well as standardized geologic data creation using GIS software.


Don Clark

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

Don Clark is a Professional Geologist 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.


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.

Cartographer, GIS Analyst

Rosemary Fasselin

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