Interim Geologic Map of the Huntsville Quadrangle, Weber and Cache Counties, Utah

The Huntsville 7.5' quadrangle lies within Ogden Valley, a back valley of the Wasatch Range in Weber County, Utah, about 6 miles (10 km) east-northeast of Ogden City. Settled in 1849, Ogden Valley was a pioneer frontier settlement and served primarily as a small farming community until recently. The area is currently characterized by rapid suburban growth. The quadrangle is centered on Ogden Valley with the Wasatch Range on the east and west side of the valley. The Ogden Valley f loor lies at an elevation of about 4900 feet (1494 m) with surrounding mountains reaching elevations of more than 9500 feet (2896 m). Pineview Dam, built in 1937 at the head of Ogden Canyon, impounds all surface flow from Ogden Valley and forms the distinctly shaped, three-armed Pineview Reservoir. In the northwest part of the quadrangle, the North Fork of the Ogden River flows south toward Pineview Reservoir. The Middle and South Forks of the Ogden River bisect the quadrangle and enter Pineview Reservoir. Several smaller ephemeral and perennial streams are present in the quadrangle including three perennial streams, Wolf, Geertsen Canyon, and Bennett Creeks. The quadrangle in Ogden Valley includes the communities of Huntsville, Eden, and Liberty. Part of Powder Mountain ski resort, which draws year-round visitation and recreation, is present in the northeast corner of the quadrangle. The valley’s climate is semiarid with most summer precipitation occurring as brief, intense thunderstorms of short duration and winter precipitation occurring as snowfall. Records at Pineview Dam collected since the mid-1900s indicate average annual precipitation of about 30 inches and about 120 inches of snow per year (Western Regional Climate Center, 2019); precipitation on higher slopes of the valley is greater. This new map provides geologic data for a variety of derivative uses. The surficial mapping focused on geologic hazards relevant to the ongoing growth and development of Ogden Valley. Many of the geologic processes that shaped the valley’s scenic and rugged landscape over millions of years are still active today and are potentially hazardous to property and life. Principal hazards include those associated with landsliding, debris flows, problem soils, flooding, earthquake ground shaking, liquefaction, shallow groundwater, and rockfalls. Prudent development addresses geologic hazards early in the planning process, redesigning subdivisions and other development around geologic problems, as post-development repair of damage caused by a geologic hazard is costly and often impractical. This mapping will be used by the Utah Geological Survey (UGS) Geologic Hazards Mapping Initiative (Christenson and Ashland, 2007; Castleton and McKean, 2012) as the first step in creating geologic hazard maps to assist homeowners, local municipalities, developers, planners, designers, and engineers with proper development to reduce risk and best use the land.