Springs

Photo of Alley Spring's pool of blue water.

Springs are openings in the ground or rock where underground streams or seeps release water into caves or on the ground. Missouri has many great examples of springs.

Springs, along with caves, sinkholes, and natural bridges, are all features of karst regions. Much of Missouri is a karst landscape of porous limestone and dolomite with deep fissures.

Springs Are Part Of The Karst Cycle

Slightly acidic groundwater flows through cracks in limestone or dolomite, slowly dissolving the rock. The cracks widen to form cavities and eventually a subterranean drainage system.

When a cave is below the water table, it is filled entirely with water. (Well-drillers search for these water-filled pockets.) When the cave is above the water table, the cave has air in it and its water flows ever downward. Wherever underground water exits the rock and flows into the open air, it is called a spring. Spring water can discharge from the ground due to gravity or hydrostatic pressure (the pressure exerted by standing water).

Some of our largest caves formed ages ago as completely water-filled cavities. Over geologic time, the Ozark Plateau was uplifted, and rivers carved valleys ever deeper into the bedrock, creating bluffs and causing cave passages to be above the water table and to drain.

All the land through which water moves into groundwater or into springs or caves is called a recharge area. For a single cave system, this area can be many miles wide. Pollutants, such as agricultural chemicals and animal waste, roadway runoff, leaking septic tanks, contaminants from trash thrown into sinkholes, and even excess silt from a variety of construction and agricultural earthworks, can seep into the groundwater, polluting caves, springs, and well water.

Human Connections

In the days before refrigerators were available, springs and caves, which are always about 55F, were prized locations for cold storage of food and beverages.

Few people are aware of it today, but between 1800 and 1930, our mineral springs, and at least 80 resorts and spas that developed around them, drew hundreds of thousands of visitors to Missouri seeking “healing waters.” Our earliest settlers, notably Nathan Boone, boiled the water from natural salt springs to yield the salt necessary for frontier survival.

Spring Subtypes

There are many ways of categorizing springs, but it’s helpful to think of the following divisions.

Seeps

Some springs are the merest trickle, and they produce wetland communities called seeps. Here, soils are saturated with groundwater that wells up through layers of mucky soil. Because the water discharge is so diffused and flows so slowly, you might not even recognize it as a kind of spring.

Seep communities are roughly divided, by their water chemistry, into acid seeps, calcareous seeps (including fens), and saline seeps.

Underground Streams

What we usually think of as “springs” are underground streams, which are usually associated with aquatic caves. Some produce just a trickle of water, but the largest can churn out hundreds of millions of gallons each day. As with seeps, the water produced by an underground stream can be fresh or mineralized or salty.

In the Ozarks, springs often appear as a crevice or opening in a rock wall, where water flows out. Much of the clarity and coolness of Ozark streams comes from spring water that feeds into them.

Missouri’s large, cool, aqua-blue springs are a source of wonder — and tourism revenue — for our state. Some of our most beautiful rivers and float streams are spring fed.

  • The water that pools around a spring often appears blue because of the depth of the water and the way the minerals in the water reflect the light shining on it.
  • Spring water is cold (about 56F) because that is the constant temperature of the ground deep beneath the surface.
  • Although spring water might seem safe to drink, it is not: Any pollution entering the ground for perhaps miles around the spring may be in the water, along with viruses, bacteria, and other microbes that can cause illness. You should treat it as you would any other creek water.

While seeps can be regarded as terrestrial wetland communities, flowing springs are viewed as aquatic habitats similar to creeks and streams, with plants that grow underwater, partially out of water, or on the banks. Where springs flow into streams and rivers, their cool, clear, well-oxygenated water creates a special habitat inhabited by a unique community of plants and animals: certain ferns, watercress, gilled aquatic snails, isopods, crayfish, salamanders, sculpins, and more. Trout, which are coldwater fish, can be successfully stocked in some spring-fed Ozark streams because of the springs’ cooling influence on the water.

Because many springs are associated with caves, many aquatic cave-dwelling animals appear where the caves open into springs, especially after heavy rains or floods.

Nearly 4,000 springs have been officially mapped in Missouri (so far). The majority are in the southern half of Missouri, mostly in the Ozark Highlands ecoregion, where they occur in soluble dolomite or limestone.

The largest and most spectacular springs are on public land as Missouri State Parks or Conservation Areas. Many smaller springs occur on private land, too, and are not open to the public.

Media
Photo of a pink planarian on a rock.
Species Types
Scientific Name
Dugesia, Planaria, and other genera
Description
Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.
Media
Photo of several prosobranch pond snails crawling on a rock.
Species Types
Scientific Name
Over 20 Missouri species in former subclass Prosobranchia
Description
Gilled snails are one of two main groups of aquatic snails in Missouri (the other group is the "lunged" snails). Gilled snails, or prosobranchs, breathe with gills and possess a hard trapdoor-like operculum. They are most common in the Ozarks.
Media
Photo of amphipod on a rock
Species Types
Scientific Name
Species in the crustacean order Amphipoda
Description
Often overlooked by people, but eagerly sought by fish, Missouri’s amphipods resemble shrimplike sowbugs. Scuds live in various aquatic habitats, and several species inhabit caves.
Media
Photo of an aquatic isopod in an aquarium, crawling on a rock.
Species Types
Scientific Name
Freshwater members of the crustacean order Isopoda
Description
Everyone knows about terrestrial sowbugs and pillbugs, but many isopod species are aquatic. Missouri has several isopods that live in streams, ponds, rivers, and caves.
Media
Photo of a spothanded crayfish viewed from above on white background.
Species Types
Scientific Name
About 36 species in Missouri
Description
Crayfish are freshwater aquatic invertebrates that look a lot like small lobsters, to which they are related. There are about 36 species of crayfish in Missouri.
Media
Grotto sculpin side view photo with black background
Species Types
Scientific Name
Cottus specus
Description
The grotto sculpin is a rare fish adapted cave conditions. It has recently been designated an endangered species under the Federal Endangered Species Act. It's found only in Perry County, Missouri.
Media
Ozark cavefish side view photo with black background
Species Types
Scientific Name
Amblyopsis rosae
Description
The Ozark cavefish is small, colorless, and blind. It lives only in springs, cave streams, and underground waters. It has been declared Endangered in our state and as Threatened by the U.S. Fish and Wildlife Service.
Media
Southern cavefish side view photo with black background
Species Types
Scientific Name
Typhlichthys subterraneus
Description
The southern cavefish has a long, flattened head without eyes. It is whitish-pink because it lacks pigmentation. The only other Missouri fish that lacks eyes is the Ozark cavefish.
Media
Image of a cave salamander
Species Types
Scientific Name
Eurycea lucifuga
Description
This common amphibian of the Ozark Plateau lives in caves, springs and rocky streams. Recognize it by its normally bright orange skin dotted with dark brown or black spots.
Media
Image of a grotto salamander
Species Types
Scientific Name
Eurycea spelaea
Description
Many people know Missouri as “the cave state,” and the grotto salamander is Missouri’s only species of blind salamander. A true troglobite, it lives in total darkness and has small eyes that are completely or partially covered by their pink or beige skin.
Media
A reddish-brown salamander with an orange stripe down its back is curled on a moss-covered rock.
Species Types
Scientific Name
Plethodon angusticlavius
Description
The Ozark zigzag salamander is small, slender, and dark, with a narrow, somewhat lobed dorsal stripe that can be yellow, orange, or red. This woodland species lives in Missouri’s southwestern counties along the Arkansas border.
Media
Photo of a southern red-backed salamander on an oak leaf.
Species Types
Scientific Name
Plethodon serratus
Description
The southern red-backed salamander is small, dark, and slender, with a distinct, narrow, red or orange mid-dorsal stripe with saw-toothed edges. It hides under rocks, mosses, and rotten logs in Ozark forests.
Media
Photo of a western slimy salamander
Species Types
Scientific Name
Plethodon albagula
Description
You might not want to touch this salamander—it secretes a thick, very sticky substance that adheres to skin like glue. It causes dust, dirt or bits of dead leaves to stick to one’s hands and is difficult to remove.
Media
Image of a pickerel frog
Species Types
Scientific Name
Lithobates palustris (formerly Rana palustris)
Description
The pickerel frog is medium-sized, with square or rectangular spots in two parallel rows down the back. There is a wide ridge of skin along each side of the back. It is absent from the northwestern third of Missouri.
Media
Image of a wood frog
Species Types
Scientific Name
Lithobates sylvaticus (formerly Rana sylvatica)
Description
The wood frog is tan, pinkish-tan, or brown, with a dark brown mask through the eye and ear. It is perfectly camouflaged among dead oak and maple leaves. A rare frog, it lives in cool, wooded hillsides in portions of eastern Missouri and some southwestern counties.
Media
Photo of a beaver half in water
Species Types
Scientific Name
Castor canadensis
Description
The American beaver is a semiaquatic rodent distinguished by its large size, webbed hind feet, and large, horizontally flattened tail covered with leathery scales.
Media
photo of river otter
Species Types
Scientific Name
Lontra canadensis
Description
The North American river otter was once nearly eliminated in Missouri, but thanks to restoration efforts, these powerful swimmers are once again found throughout most of the state.
Media
Photo of path rush, closeup showing drying fruits.
Species Types
Scientific Name
Juncus spp. and Luzula spp.
Description
Missouri has 24 species in the rush family. Distinguishing between these grasslike plants can be tricky, but it’s easy to learn some basics about the group.
Media
Photo of eastern woodland sedge plant growing among leaf litter.
Species Types
Scientific Name
Carex, Schoenoplectus, Scirpus, and other genera
Description
Missouri has more than 200 species in the sedge family. Distinguishing between these grasslike plants can be difficult, but it’s easy to learn some basics about the group.
Media
Photo of watercress flowers
Species Types
Scientific Name
Nasturtium officinale (syn. Rorippa nasturtium-aquaticum)
Description
Spring branches and streams in the Ozarks are decorated with large colonies of these plants, which can grow like thick green garlands in the water. It has a long history of use as a salad green, and it is cultivated to sell to gourmet cooks. If you collect watercress from the wild, make sure to wash it thoroughly.
Media
Photo of spotted touch-me-not or jewelweed flower.
Species Types
Scientific Name
Impatiens capensis
Description
Many Missouri children learn about this orange-flowered native plant by playing with the juicy green seedpods, which, when ripe, "explode" upon the slightest touch. This is jewelweed's mechanism for seed dispersal, and it's the reason for the name "touch-me-not."
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