Bennett Spring State Park - Fisherman's Paradise

Conor Watkins' Ozark Mountain Experience
Article 39-41 Combined
Bennett Spring State Park - Fisherman's Paradise

Bennett Spring State Park
-Fisherman's Paradise

Fishermen wade into Bennett Spring in an attempt to hook some of
the spring's trout population. The historic stone gaging station
may be seen in the background on the left bank.
Another Picture of Bennett Spring

Bennett Spring State Park, located in Dallas County near Lebanon, MO is home to the Ozarks’ 4th largest spring, a fish hatchery, and a unique natural tunnel. Bennett Spring’s biggest claim to fame is the fish hatchery, which has made the area into a very popular trout-fishing destination. An average of 103 millions of gallons of cold water flow from the spring each day, providing excellent habitat for trout and other fish. Bennett Spring is one of four designated trout parks in Missouri along with Maramec Spring Park, Montauk State Park, and Roaring River State Park, all of which are spring fed.

The first time visitor to Bennett Spring should make the nature center their first destination within the park. Hiking maps and other information are available there. In addition, various displays exhibit the natural and cultural history of the spring and surrounding area. Interpretive programs are also offered.

Bennett Spring State Park may not appeal to those seeking a remote and natural location. Both the spring and the surrounding area are highly developed. On the other hand, the highly developed nature of the park does offer many amenities not found in many other state parks. There are remote areas in the more than 3,200-acre park but they are not located near the main entrance and must be accessed by hiking. As stated earlier, the park’s trout hatchery is its largest attraction. Some the spring water is diverted through the fish hatchery by a low dam where is it used to provide fresh cold water to the trout. This water eventually ends up back in the spring branch, which flows for about two miles to the Niangua River.

Trout fishing season runs from March 1st through Oct 31st at Bennett Spring. The spring and its branch (outlet stream) are divided into three separate zones with differing regulations in each zone. A daily trout tag, which can be purchased at the park store, must be displayed while fishing. Adult trout tags cost $3 while tags for those 16 and younger are $2. A daily fishing license for those without a yearly license costs an additional $5. Other rules and regulations that apply to fishing in the park may be found at http://www.mostateparks.com/bennett/troutregs.htm. The park store sells fishing equipment, camping supplies, food, and other miscellaneous supplies. A fly fishing school is also available.

The park also offers five camping areas. These area including basic, electric, and full electric/sewer camping sites with prices ranging from $7 to $13 during the off season and $8 to $15 during the on season. These prices depend on a variety of factors including services offered and senior citizen discounts. Camping services include a dump station, laundry, shower facilities, and reservable sites. Although the campground is open year round, water is only available between April 15th and October 15th due to the probability of freezing temperatures in the winter.

The park includes a rustic dining lodge built in the 1930s by the Civilian Conservation Corps (CCC) during the Great Depression. This lodge, known for serving quality food, is open for breakfast, lunch, and dinner during trout season. It also offers a meeting and conference room. Also included are motel rooms along with single, duplex, and quadplex cabins. Canoe rental is available from within the park and from surrounding businesses along the Niangua River. A modern swimming pool, built in the 1960’s, is provided in the park and may be used for a small fee. The pool is generally open from the Memorial Day to Labor Day holidays. The park has two main picnic areas and five playgrounds scattered throughout the park. Two picnic pavilions are reservable $25 and $35. For more information on the concessions within Bennett Spring State Park, see www.bennettspringstatepark.com.

Bennett Spring State Park offers around 12 miles of hiking trails that consist of three main trails along with several shorter trails. A flat trail along the spring branch to the Niangua River, is around two miles long and offers good views of the spring and main parts of the park. Not all of this trail system follows the spring branch. The 2.5-mile Savanna Ridge Trail takes the visitor through more remote Ozark terrain and offers scenic views, a losing stream, rocky dolomite glades, and hardwood forests. The Natural Tunnel Trail takes the visitor on a 7.5-mile round trip through the valley upstream of Bennett Spring and features unique bluffs, a losing stream, small caves, and the large Bennett Spring Natural Tunnel. Both the Savanna Ridge and the Natural Tunnel Trail have cutoffs, which allow the hiker to shorten their trip.

Visitors looking to see more remote and natural parts of the park will enjoy the hike to Bennett Spring Natural Tunnel at the end of the Natural Tunnel Trail. This is an interesting 7.5-mile long trail, if the entire loop is taken, but longer if side trails are hiked. It ends at an excellent example of a natural tunnel. The Bennett Spring Natural Tunnel is similar to the Kaintuck Natural Tunnel in Phelps County near Newburg, MO but scaled up by a factor of about 2.5x in all directions. This S-shaped tunnel is 296 feet long, 16 feet high and about 50 feet wide. Jointing in the rock controls the orientation of the tunnel and the remnant cave system. Water from a creek flows through the tunnel but one can walk through without getting wet.

View seen when looking out the downstream entrance of the tunnel.
Although a stream flows through the tunnel, one can usually walk
through without getting wet. Notice person just outside of tunnel for scale.

Overhanging cliffs just downstream of the Bennett
Spring Natural Tunnel drip water from above.

The whole valley above the Bennett Spring appears to have once been a very large cave system that has collapsed. This is especially noticeable on the upstream end of the natural tunnel where there are many shelter caves. The cave walls are still present as a canyon type feature (like a mini Grand Gulf) and there are a couple parts where the cave ceiling is still partly intact as ledges that hang out over the canyon. There are plenty of shelter caves (some with multiple entrances) along the trail both upstream and downstream of the tunnel, which are obviously of karst origin. Some of the caves contain active formations but most now have old and dead formations and a lot of clay fill. These features continue for miles and miles along the trail. Perhaps this now eroded cave was the feeder system for a prehistoric spring at a higher elevation than Bennett. The tunnel represents a small section of a cave which was once much larger.

These overhanging ledges upstream from the tunnel are small parts of
the roof of a once larger cave system. If one uses their imagination, it is
not hard to see these ledges as part of a complete cave roof.

The natural tunnel will eventually succumb to collapse as the rest of the cave has already done. One can also see that the roof of the natural tunnel is thin in places, especially the upstream and downstream end, and is starting to fail along the bedding planes of the Gasconade dolomite. This failure is due to the fact that rock cannot withstand very much tension comparative to its compressive strength. As a general rule of thumb, rock is usually about ten times strong in compression than in tension. When rock is placed into what is essentially a long beam, it cracks in the middle on the bottom side due to high tensional stresses induced by the rock bowing downward under its own weight. These cracks at the Bennett Spring Natural Tunnel will eventually propagate upward through the rock and lead to its complete failure and collapse. Perhaps its last remnant will look something like the present day Clifty Creek Natural Arch near Dixon, MO.

For those who have been to Clifty Creek and its natural arch near Dixon, the valley near the Bennett tunnel looks similar to this area with its overhanging ledges and remnant karst. Clifty Creek is also very worth seeing. The similarities seen in the Kaintuck Natural Tunnel, Clifty Creek, and the hollow above Bennett Spring are probably partly due to the fact that they are all formed in the Gasconade Dolomite.

The Bennett Spring Natural Tunnel is a case of subterranean stream piracy where a surface stream has taken a shortcut by flowing underground through the tunnel. The creek that flows through the tunnel has cutoff one half mile of its previous course.

Portion of Bennett Springs Topographic Map (click image to enlarge)
from the Missouri Spatial Data Information Service
(ftp://msdis.missouri.edu/pub/drg/springfielde/o37092f7.tar.gz).
Notice the spring and main part of the park in the NW corner of the map
(Sec 1, T34N, R18W) and the Bennett Spring Natural Tunnel in the SE corner
(NE 1/4, NW 1/4, NW 1/4, Sec 8, T34N, R17W). One can still see
the abandoned meander loop just SSE of the tunnel where the
creek no longer flows.

A concrete and rebar dam (built around 1964) at the upstream end of the Bennett Spring Natural Tunnel was an interesting but failed attempt to fill up the upstream canyon with water. The dam builder here took a bunch of creek gravel and silt, piled it up in the mouth of the tunnel and then covered this material with a layer of rebar reinforced concrete, some of which remains today. This dam completely blocked the upstream entrance to the tunnel and the creek must have reverted back to its old course through the meander around the tunnel for a time.

The author stands atop the remains of the wrecked concrete and rebar dam
used to fill the upstream canyon with water.
View #2 - Same view but without author.

As a Geological Engineering student, it is the author's opinion that the dam failed for the following reasons. This design would have worked if it weren’t for the settling of the fill, which caused the concrete to crack, something that is almost guaranteed to happen with the design used for this dam. The cracks appear to have allowed the water to enter the fill. The fill composing the core of the dam was very permeable and subject to piping (internal erosion due to water pressure). Once water pressure entered the core, the silt piped out, leaving no support under the concrete dam, which then collapsed, allowing a complete failure. The dam may have also partly failed due to piping under the dam. It is not obvious if the dam builders dug down into the natural fill below to create a cutoff trench in order to prevent leakage and piping. This seems unlikely based on the construction of the rest of the dam. It may be quite a ways down through the natural fill to the old cave floor below. History reports that the dam failed during a heavy rainfall event. If this is true, this points to a piping failure since the water level behind the dam, and thus the pressure difference, would have been higher than normal.

There is still some of this dam left, but it is completely useless except for a small frog pond created by a small part of the still intact but cracked lower section. Some fill used to make the core of the dam is still present on the right side of the tunnel (as you face downstream). It seems this dam was not constructed by someone with even the slightest engineering background when it comes to the behavior of soils and concrete.

The Bennett Spring Natural Tunnel and its trail are a must see for anyone interested in karst geology as the end stage of a remnant cave is highly visible. Bennett Spring has a recharge area of around 265 square miles. James Vandike of the Missouri Dept. of Natural Resources and a UM-Rolla Professor has done extensive dye tracing on the spring. The recharge area upstream from the spring is home to spectacular sinkholes, losing streams, and other karst features.

The Bennett Spring Natural Tunnel as viewed from the downstream end.

Bennett Spring Creek, the losing stream above the spring periodically floods and deposits large amounts of cherty gravel in Bennett Spring. From time to time, a clamshell shovel is used in order to selectively remove gravel from the spring pool area. This is done in order to enhance trout habitat.

In the 1960’s, water quality reports showed an increase in the amount of pollutants in the water. Extensive dye tracing was conducted to determine the source of the pollution over the spring’s 265 square mile recharge area. Most pollution originated from non-point sources such as fertilizer used on farm fields, so some of the nearby land was purchased by the state. An extensive sanitary sewer system was constructed within the park to reduce the number of pollution sources near the spring branch. The largest purchase of land, 1,650 acres, was made in 1988 and included the natural tunnel. Chemical treatment of the park’s well water also began in the late 1980’s due to contamination.

Divers have entered the spring conduit of Bennett Spring. Most are restricted to a vertical depth of around 85 feet and a total distance of 130 feet. At this depth, a constriction in the spring conduit causes the water to flow with tremendous pressure, which churns the mostly chert gravel, and makes further diving nearly impossible. Although it is not published in any park guides or descriptions of Bennett Spring, cave diver Micki Feakes and others have made it to a depth of around 120 feet. She was able to push past the tough constriction in the conduit by wiggling through during a drought period when spring flow was low. Micki could have gone further, but her air supply was starting to run low and she left for safety reasons. In order for any diver to return to this depth, the spring will have to be at a relatively low flow. Others have claimed to have gone farther but provided no photographic evidence of their explorations.

Divers describe the spring conduit as a steeply descending cave passage starting with a relatively large room. This large room has walls sculpted and pitted by solution and abrasion. Scallop patterns are common in the cave walls. After the larger room, there are two constrictions, with the second constriction being mostly impassible. After the second and most difficult constriction, the spring conduit opens up into a large room with smooth polished walls and a gravel floor. Although no measurements were taken, Micki estimates that this room is between 30 and 40 feet wide and around 20 feet tall. A moderately sized tunnel starts after this point and continues to drop to deeper depths. No one has been in the tunnel and special air mixes may be required for divers to go any deeper into the spring, as the passage continues to descend at a steep angle.

Divers have recovered smooth polished stones, cans, polished bricks, and a froe mallet (used to make shake shingles) from the bottom of the spring. Similar deposits of polished gravels and cobbles are present several hundred feet northeast of the present spring outlet. This may represent a prehistoric outlet for the spring. Divers wanting to dive the spring must be properly trained and are required to show proof of their certification. Diving in caves/spring passages is especially dangerous and one mistake may result in death. Most divers are not allowed in the spring during fishing season, as they would disturb both fish and fisherman. Those with research permits may dive at any time, depending on what their permits state. Anyone wanting to dive Bennett Spring must contact the park office to receive the proper permission.

As with most unique natural areas in Missouri, Bennett Spring has a unique history. Osage Indians credit a large earthquake for the creation of the spring. Their belief was that the Creator caused this quake when he became angry with the tribe. Indians named the spring “Eye of The Sacred One” as they thought it resembled an eye that was crying. It served as a fishing, hunting, and meeting area for thousands of years. The first settlers started using the spring in 1837, when the James Brice family built a mill using an undershot wheel. The spring became known as Brice Spring and the town of Brice sprang up nearby. The family of Peter Bennett soon settled near the spring and started their own mill. Originally, the families were milling rivals, but they soon intermarried. Both of these mills were eventually destroyed in a flood.

During the Civil War years, another mill was constructed by Peter Bennett. The machinery for the second Bennett Mill was purchased in St. Louis and shipped to the terminus of the railroad in Rolla, MO. Oxen hauled it the remaining 70 miles to the spring. This Bennett Mill was larger (3-stories) and more successful than the Brice mill. The spring soon took on the Bennett name. Bennett was known for his generosity during the Civil War, as he gave hundreds of bushels of grain away to needy families during this time. Peter died in 1882 and his son William Sherman Bennett took over. The Bennett Mill burned in 1895. It was rumored this fire was an act of arson, committed by someone with a grudge against Bennett.

Another mill was opened in 1900 by the Atchley family. The overshot wheel from the Bennett Mill was salvaged and used in this mill. This wheel, which had fallen into the stream after the fire in 1895, was very large. After several unsuccessful attempts to remove the wheel, a team of six steers hired for $50 was able to pull the wheel out of the spring branch. This mill was used for various purposes including milling, electric power generation, and storage until it burned in 1944.

The Bennett and Atchley mills used a dam made of logs to provide power for their overshot wheels. For the later part of its life, the concrete CCC dam supplied the Atchley mill with water.

The spring was first stocked with “mountain trout” around 1900 and it soon became a popular fishing spot. Around the same time, the Brice Inn was established to serve tourists. In 1923, a private fish hatchery was built. In the early 1920’s, both state and federal officials were looking for natural land to preserve as parks. Much of the land in the Ozarks was being lumbered and used for other agricultural purposes. In 1924 and 1925, the state purchased the town of Brice and Bennett Spring from the Bennett family. The Missouri State Park Board established Bennett Spring State Park, one of the first Missouri state parks. The Superintendent of the park ran both the park and the hatchery until the Missouri Department of Conservation (MDC) was established in 1937. Although the MDC managed the spring, the rest of the park remained under the State Park Board. Bennett Spring and all other state parks were taken over by the Missouri Department of Natural Resources (MoDNR) when it was created in the 1970’s.

In the 1930’s the Civilian Conservation Corps (CCC) made various improvements to the park, many of which still remain today. The CCC improvements include renovation of the mill, the construction of the dining lodge, six cabins, trails, roads, shelters, and the arched stone bridge across the spring branch. The stone used to build these structures came from the Jackson Quarry along Hwy 32 near Lebanon. The CCC also channelized the spring branch and constructed the dam just upstream of the stone bridge to make the spring more habitable to the non-native trout. The dam is used to divert water through the fish hatchery and to maintain a constant water level at Bennett Spring. About 23 millions gallons per day pass through the hatchery. The rest of the water cascades over the top of this concrete dam. At one time, the last remaining mill used some of the water to generate electricity. A gauging station was built near the spring to measure daily flow. This stone structure is no longer used but is still present. It has since been replaced by a smaller and more accurate modern gauging system located nearby.

The concrete CCC dam serves to make the spring more inhabitable
for trout, a non-native fish species.

The stone CCC bridge still serves to carry auto traffic across
the spring branch.

Only one building from the town of Brice remains today. This building is the Bennett Spring Church of God, which started out as a white clapboard structure. The Bennett family originally donated an acre of land for the church. An outside layer of rock was added to the building during the 1950’s to make the church more resemble the surrounding park buildings constructed by the CCC. Fish food was stored in the old Atchley Mill until it burned in 1944. When World War II broke out, funding to restore other buildings was limited. The hotel was torn down in 1946 due to its poor condition.

With improved roads to Bennett Spring being constructed, the park’s popularity increased in the 1950’s and 60’s. Both the park swimming pool and modern restrooms were installed in the 1960’s to provide more amenities to park visitors. In the 1970’s and 80’s, many of the old cabins built by the CCC and private individuals were replaced. A few CCC era cabins were kept and completely renovated. In 1982, a new office and park store were dedicated, as the old facilities were no longer adequate due to increasing visitation.

Much of the land within the park was once farmland used for grazing, logging, hay, and crops for about 150 years. During this period of overuse, much of the land became overgrown with non-native plant species and/or was denuded of its native vegetation. New management practices are underway to help restore a more natural environment. These practices include prescribed burns to burn leaf litter and remove non-native vegetation. Native vegetation is currently being reestablished in much of the park, including the area along the trail leading to the natural tunnel. The areas around the campgrounds are also burned from time to time. The main purpose in doing this is not to simulate a more natural environment, although that is a side benefit, but clear the area of natural fuels so it is harder for a careless camper to start a wildfire.

Every year during the third weekend in June, Bennett Spring State Park hosts Hillbilly Days in conjunction with the nearby city of Lebanon, MO. Hillbilly Days is a festival celebrating the history of the spring and its surrounding Ozarks. Crafts, car/truck/tractor shows, farm shows, Ozark music, food, and a good time are included. Hillbilly Days started in 1974 as a fiftieth anniversary celebration for the park and was meant to be a one-time event. This event, which is somewhat similar to Old Ironworks Days held at Meramec Spring, became an annual tradition due to its popularity.

Bennett Spring State Park offers something for everyone. It has aspects appealing to those wanting a rugged retreat and those wanting their meals and air-conditioned lodging provided. It also appeals to both the fisherman and the geologist. The park’s popularity increased in the 1970’s and has since seen an average of just under one million visitors per year.

Getting there: Bennett Spring State Park is located in both Dallas and Laclede Counties near Lebanon, MO. The spring itself is located in Dallas County. From Rolla, take I-44 west to exit 129 in Lebanon, MO. From here, turn right (north) on Hwy 5. Drive for 12 miles to Hwy 64. Turn right here and follow to Hwy 64A. Turn left here and follow to Bennett Spring State Park.

"(B)" marks the spot for the location of Bennett Spring State Park.
(Click above image to enlarge map)

For more information on Bennett Spring, the following publications are suggested: Conway Chronicles (http://www.llion.org/conway/jun15.html)
Ozark Caving Website (http://www.umsl.edu/~joellaws/ozark_caving/springs/bennett.htm),
Bittersweet – Milling Around the Ozarks (http://198.209.8.166/sheproom/periodicals/bittersweet/sp75b.htm),
“Springs of Missouri” by Jerry D. Vineyard and Gerald L. Feder, and
“Geologic Wonders And Curiosities of Missouri” by Thomas R. Beveridge Jerry D. Vineyard. Thanks to cave diver Micki Feakes for her telephone interview concerning the exploration of the Bennett Spring supply conduit and Dianne Tucker, Bennett Spring State Park Naturalist, for her information on the park.