GeoSights: Ricks Spring, Cache County
by Stephanie Carney
View looking toward the alcove at Ricks Spring. The photo was taken Geosciences Department. in fall and the water flow is low. Photo courtesy Dr. Susanne Janecke, Emeritus Professor, Utah State University Geosciences Department.
Logan Canyon, which winds its way through the Bear River Range along Highway 89 in Cache County, gives access to many interesting karst features including springs and caves. One well-known feature is Ricks Spring, which has been a roadside attraction for more than 100 years since it was discovered and named in the late 1800s. The spring issues from a submerged cave system and karst aquifer in the Ordovician-age Garden City Formation, and flows from a large, easily accessible grotto right next to Highway 89.
The term “karst” refers to a type of landscape formed in areas that have easily dissolvable rocks like limestone, dolomite, or gypsum. Landforms in these areas include sinkholes, caves, and towers that are created by the dissolution of rock by mildly acidic groundwater and surface water. When rainwater falls, some of it reacts with carbon dioxide in the atmosphere to become carbonic acid. As this weak acid flows through cracks and fractures in limestone or dolomite rock, a chemical reaction occurs that causes the rock to slowly dissolve. Over thousands of years, the flow path of the groundwater through the limestone can widen and form a cave system large enough for people to enter.
Visitors to Ricks Spring in the early 1900s. Note the woman scooping a cup of the spring water.
The Garden City Formation is composed of limestone (calcium carbonate, CaCO3) that was deposited about 465 million years ago in a shallow, tropical, nearshore environment. About 100 million years ago, long after lithification and burial, the sedimentary layers were simultaneously uplifted, compressed, and gently folded into the Logan syncline during a tectonic mountain-building event called the Sevier orogeny. Then, starting about 20 million years ago and continuing to present day, the Bear River Range, which includes the Logan syncline, was uplifted by normal faulting created by east-west extension in what is now called the Basin and Range Province.
Over thousands of years, acidic groundwater etched out and widened the fractures and faults in the Garden City Formation, forming multiple cave systems. One popular example is the extensive submerged cave system that “daylights,” or breaches the surface, at Ricks Spring. The spring rises into a pool inside a large alcove and flows under Highway 89 to empty into the Logan River. The cave was first explored by a Utah team of cave divers in 2007, and over several years and dozens of dives, they mapped out nearly 2,300 feet of the cave system.
The spring is named after Thomas Ricks, who lived in the Cache Valley area in the mid- to late 1800s. At the recommendation of Mormon leader Brigham Young, he and several others began constructing a road eastward along the Logan River with the goal to connect Cache and Bear Lake Valleys. The first “leg” of the road ended at Ricks Spring. Residents in the area originally believed the spring water was sourced from a deep and pristine aquifer. They would trek to the spring to partake of fresh spring water, only to be later sickened from Giardia. Because this parasite enters surface waters through the feces of animals, folks soon realized that the spring water was likely from a surficial source.
View looking south from Ricks Spring. Note low flow of the spring in fall months. Photo courtesy Dr. Susanne Janecke, emeritus professor, Utah State University Geosciences Department.
In the 1950s, hydrogeologists proposed a possible link between the Logan River and Ricks Spring based on similar seasonal flow rates. During spring runoff, both the river and the spring would have very high flow rates. Conversely, when river flow rates slowed during winter, Ricks Spring would slow to a trickle or cease flowing entirely. In the summer of 1972, this connection was confirmed through a dye trace test conducted on the Logan River. The non-toxic fluorescent dye added to the river upstream of the spring showed up in the water discharging from the spring. Scientists theorize that the dye likely entered the karst aquifer through a northeast-trending fault that intersects both the aquifer and the river. In the 1990s, more dye trace tests were conducted by a U.S. Geological Survey hydrogeologist in several basins north and northwest of Ricks Spring to see if there were other surficial sources of the spring water. These tests confirmed that Bear Hollow, Tony Grove Creek, and Bunchgrass Creek provide water to the system, most of which comes from the melting of winter snowpack during spring and early summer.
How to Get There
GPS Coordinates: 41° 50´ 25˝ N., 111° 35´ 19˝ W
From Main Street in Logan, Utah, head east into Logan Canyon on 400 North/U.S. Route 89 for about 17 miles. Pull-off areas are located on the north and south sides of the highway for parking. Be very careful if crossing the highway. Signs about the spring and its history are posted. The spring flows during the spring, summer, and fall.
