logan river Archives - Wild About Utah

Logan Rivers evolving geomorphology: Logan River’s Evolving Geomorphology: Children enjoying Logan River as they search for insects among the dropped sediments of the Logan River. Courtesy & Copyright Shauna Leavitt, Photographer — Children enjoying Logan River as they search for insects among the dropped sediments of the Logan River.
Courtesy & Copyright Shauna Leavitt, Photographer

Logan River’s geomorphology, or landform, has changed very little over the past 150 years in the mountain canyons. But where the river leaves the mountains and drops down onto Cache Valley’s floor, its geomorphology has changed dramatically.

A river’s geomorphology is how it interacts with its environment, how it changes and moves over time, how it picks up sediment and debris when its flowing fast then releases the sediments downstream where the river slows and spreads over open-flat landscapes.

Logan Rivers evolving geomorphology: Logan River’s Evolving Geomorphology: Father and son enjoying a day of fishing on the reservoir behind First dam in the mouth of Logan Canyon Courtesy & Copyright Shauna Leavitt, Photographer — Father and son enjoying a day of fishing on the reservoir behind First dam in the mouth of Logan Canyon
Courtesy & Copyright Shauna Leavitt, Photographer

The route of Logan River is noteworthy. Peter Wilcock, department head of Watershed Sciences in the Quinney College of Natural Resources explains, Logan River cuts through a large amount of the Bear River mountain range [in northeastern Utah and southeastern Idaho] and is by far the biggest drainage from the range.

The river’s size has made a mark on the mountain. When all the tributaries and springs come together, the result is the fast-flowing river with great force for erosion. If you compare Logan Canyon with other canyons coming out of the Bear River Range such as Green Canyon or Providence Canyon you can see Logan Canyon is close to 600 feet lower than all the other canyons. The volume and force of Logan River cut through the beach material that ancient Lake Bonneville left behind, the other drainages have been too small to cut through the ancient short line.

In the early 1800s, the lower part of Logan River flowed freely, meandering and spreading across the Cache Valley floor. As it entered the valley, the river would form into an alluvial fan spreading like fingers over the valley floor and meeting the natural functions of a river to transport water, sediments and nutrients.

As each decade passed an increasing number of buildings, roads and complex infrastructures were built to keep up with the growing population. And to protect this infrastructure, people attempted to restrict the movements of the river. In many places, the river was straightened or channelized even as its water was re-routed for irrigation.

The dams placed along the river and at the mouth of Logan Canyon slowed the river before it reached the valley floor. As a result, a large percentage of the sediments which would have dropped on the valley floor, are now captured behind the river’s dams and fill the reservoirs.

Frank Howe, chairman of the Logan River Task Force, explains how this impacts the river’s geomorphology, “Water released from the dams is free of deposits; the river is now “hungry” – hungry for new sediments. It’s now capable of picking up large amounts of sediments which causes erosion problems miles below the dams.”

The Logan River Task Force, consisting of representatives from Utah State University, Logan City, Cache County, State and Federal Agencies, six non-profit organizations, corporations and interested citizens came together to find solutions to the erosion problem and other river issues. To address these issues, they prepared a “long-term plan for the Logan River to balance ecological and social values and capture what Cache Valley community wants the river to become. “

Rivers, by nature, are dynamic. They move back and forth especially where the slope is gentle. Over time, this meandering movement delivers fine sediments, across the river’s floodplains creating rich soils diverse in vegetation and wildlife. By changing the river’s geomorphology, we’ve altered the rivers dynamics, as well as how and where it delivers sediments.

Fortunately, parts of the Logan River’s geomorphology can be restored. River restoration will be the topic of our fourth and final segment for the Logan River series on Wild About Utah.

This is Shauna Leavitt and I’m wild about Utah.

Logan River’s Evolving Geomorphology-Credits:
Photos: Courtesy & Copyright ©
Audio: Courtesy & Copyright © Friend Weller, Utah Public Radio
Text: Shauna Leavitt, Utah Cooperative Fish and Wildlife Research Unit, Quinney College of Natural Resources, Utah State University
Co-Authored by: Frank Howe, chairman of the Logan River Task Force, adjunct associate professor, and university liaison for Utah Division of Wildlife Resources.

Logan River’s Evolving Geomorphology-Additional Reading

Leavitt, Shauna, A Short History of the Logan River, Wild About Utah, November 4, 2019, https://wildaboututah.org/short-history-of-logan-river/

Leavitt, Shauna, The Ecology in and around the Logan River, Wild About Utah, December 2, 2019, https://wildaboututah.org/the-ecology-in-and-around-the-logan-river/

Williams, Edmond J, Geomorphic Features and History of the Lower Part of Logan Canyon, Utah, Thesis, MS Science 2964, Donald R. Olsen Chair, Department of Geology, Utah State University,

James P. Evans, James P. McCalpinl, David C. Holmes, Geologic Map of the Logan 7.5′ Quadrangle, Cache County, Utah, Department of Geology, Utah State University, Utah Geological Survey, Utah Department of Natural Resources, 1996, https://ugspub.nr.utah.gov/publications/misc_pubs/mp-96-1.pdf

Hylland, Rebecca, What are Igneous, Sedimentary & Metamorphic Rocks?, Glad You Asked, Utah Geological Survey, https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/igneous-sedimentary-metamorphic-rocks/

Belted Kingfisher Ceryl alcyon Courtesy US FWS, C Schlawe, Photographer — Belted Kingfisher
Ceryl alcyon
Courtesy US FWS,
C Schlawe, Photographer

Logan River ecology is about connections between highlands and lowlands, water and land, life in and around the river and resources that support that life.

The river begins in southeastern Idaho and runs 53.5 miles to its confluence with the Cutler Reservoir in Utah’s Cache Valley. The river transitions from mountain riparian, characterized by low growing willows and coniferous trees, to the valley’s lowland riparian where it’s dominated by a variety of shrubs, cottonwoods, and willow trees. Both wildlife and plants change along this elevational gradient giving the Logan River greater ecological diversity than might be found over hundreds of miles of a flatland river.

Rivers move water. They also transport sediments and nutrients that drop out of the water wherever the current slows, for example on floodplains during spring floods. This is why floodplains, or riparian zones, have such productive soils.

The rich soils and water available on the floodplain support a wide diversity of plants. These plants in turn provide underlying layers for insects, nesting sites for birds, and water-cooling shade that harbors the heat sensitive cutthroat trout. Plants also drop their leaves into the river providing food and nutrients to aquatic insects.

One insect found in the Logan River is the mayfly, a graceful macroinvertebrate with unique upright wings and a delicate silhouette. The female adult drops her eggs on the river’s surface which then fall to the river’s bottom. The nymphs hatch within a few days or weeks. They spend the next year moving along the river’s bottom hiding among vegetation, rocks, and fallen leaves. After a year, nymphs swim to the surface and molt into duns which fly to nearby riparian vegetation. After a couple hours duns shed their skins and become brightly colored adult mayflies called spinners.

Male spinners form a swarm over the water to attract females who fly into the swarm. Pairs mate in flight; after mating the female flies down to the river to deposit her eggs, and dies shortly thereafter.

A large number of mayflies do not complete their life cycle as they are eaten by fish, spiders, bats and birds.

Bonneville cutthroat trout, Utah’s state fish, subsist largely on aquatic insects including mayflies. Feared to be extinct in the 1970s, biologists searched the state for Bonneville cutthroat trout and when a population was found in the Logan River, wildlife managers and USU scientists teamed together to ensure the cutthroat population became and remained robust.

American Dipper Courtesy US FWS Dave Menke, Photographer — American Dipper
Courtesy US FWS
Dave Menke, Photographer

Hundreds of bird species eat aquatic insects; one bird, however, specializes in eating aquatic insects under water. The American Dipper, walks on the bottom of Logan River using its wings like a submarine’s diving planes to keep it from bobbing to the surface. Walking along the river bed, the dipper turns over small rocks and sunken sticks to uncover and eat insect nymphs.

Other riparian birds, like the belted kingfisher, are fish-eaters. This handsome, crested, steel blue bird can be seen perched in the trees next to the Logan River eying fish beneath the surface. At times, kingfishers will hover directly above the water announcing their presence with a loud, rattling call. At the right time, the kingfisher dives headlong into the river using its long, sharp beak like a tweezers to catch small fish.

Rivers, like the Logan, and their riparian zones, support some of the richest biological diversity in the West. They are forceful and ever-changing, but provide all that life needs to survive and thrive in a compact area. These are dynamic ribbons of green and blue that connect land to water, plants to animals, and humans to nature.

This is Shauna Leavitt and I’m wild about Utah.

Credits:
Photos: Courtesy & Copyright ©
Audio: Courtesy & Copyright © Friend Weller, Utah Public Radio
Text: Shauna Leavitt, Utah Cooperative Fish and Wildlife Research Unit, Quinney College of Natural Resources, Utah State University
Co-Authored by: Frank Howe, Wildland Resources, Assoc. Prof. (State Cooperator), Quinney College of Natural Resources, Utah State University

Sources & Additional Reading

Geologic Map of the Logan 7.5′ Quadrangle, Cache County, Utah, Utah Geological Survey, 1996, https://ugspub.nr.utah.gov/publications/misc_pubs/mp-96-1.pdf

Williams, Stewart J. Lake Bonneville: Geology of Southern Cache Valley, Utah, Geological Survey Professional Paper 257-C, US Department of the Interior, 1962, https://pubs.usgs.gov/pp/0257c/report.pdf

Biek, Bob; Willis, Grant; Ehler, Buck; Utah’s Glacial Geology, Utah Geological Survey, September 2010, https://geology.utah.gov/map-pub/survey-notes/utahs-glacial-geology/