Reports

The lower Virgin River is a sandy, shallow reach of the Virgin River that flows from northern Arizona to Lake Mead in Nevada. The Virgin River hosts several native fish species, including two endangered fish, woundfin (Plagopterus argentissimu) and Virgin River chub (Gila seminuda). All native fish species in the lower Virgin River have experienced reductions in population sizes in the...

Models to estimate low-streamflow statistics at ungaged locations in New York, excluding Long Island and including hydrologically connected basins from bordering States, were developed for the first time by the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation. A total of 224 basin characteristics were developed for 213 unaltered...

The lunar surface is a compelling opportunity for large, distributed optical facilities, with significant advantages over orbital facilities for high spatial resolution astrophysics. Serious development of mission concepts is timely because of the confluence of multiple compelling factors. First, lunar access technology is maturing rapidly, in the form of both US uncrewed and crewed...

Pseudogymnoascus destructans (Pd), the causative agent of white-nose syndrome (WNS) in bats, has caused serious declines in bat populations across North America. We conducted WNS surveillance in five different park units in the North Coast and Cascades Network (NCCN) from 2016 to 2024, following the initial detection of Pd and WNS in Washington State in 2016. We captured and swabbed bats...

During 2022–2024, the Wildfire Research (WiRē) Center partnered with the West Region Wildfire Council (WRWC) to learn more about parcel-level wildfire risk in Montrose County, Colorado. This research project was part of a larger, sustained collaboration between WiRē and the WRWC, moving the focus from areas typically characterized as fire-prone due to heavily treed and steep topography...

The Obed River is the last undammed river in Tennessee. The Obed Wild and Scenic River is managed by the National Park Service and covers a protected area of the Obed River headwaters (including four contributing tributaries). The Obed Wild and Scenic River supports a unique ecosystem with eight federally listed species. The National Park Service is responsible for preserving the...

Population growth and recurring droughts in the Black Hills region raised interest in water resources and future availability. The Black Hills hydrology study (BHHS) was initiated in the early 1990s to address questions regarding water resources. Since completion of the BHHS in the early 2000s, the population of the Black Hills region increased by about 39 percent, which has renewed...

Introduction The State of Tennessee has an area of approximately 42,100 square miles and includes six physiographic regions: Blue Ridge, Valley and Ridge, Appalachian Plateaus, Highland Rim, Nashville Basin, and the Gulf Coastal Plains. Up-to-date elevation data support key activities across the State, such as economic development, infrastructure and construction management, agriculture...

Flood-frequency analysis provides the basis for flood risk estimates used by water-resource managers in land-use planning, and it informs the design of essential infrastructure such as bridges and culverts. Federal guidelines for flood-frequency analysis do not offer guidance on addressing changing climate and land-use conditions when estimating floods. However, failing to consider...

This study by the U.S. Geological Survey (USGS) provides estimates of the change in sand storage in bed sediments from the 1980s to 2010s in the San Francisco Bay area, California. The study is part of a larger project called “Research to Understand Impacts of Bay Sand Mining on Sand Transport in San Francisco Bay and the Outer Coast” that has the goal of providing information for the...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 5.1 billion barrels of oil and 19.5 trillion cubic feet of gas in the northern Arabian Peninsula.

The use of wetlands to support native fish research and conservation efforts in the Sacramento–San Joaquin Delta (Delta) of California is a growing priority. The purpose of our study was to examine the physiochemical and biological characteristics of select managed ponds in the Delta to determine if they would be suitable habitats for research involving the conservation of delta smelt...