MADISON – Big Oaks National Wildlife Refuge has a rich history. What was once a proving ground is now a place where a wide variety of plant and animal species call home.
In the early 1940s, Jefferson Proving Ground was established because the “Army was looking for a place to test munitions,” reports park ranger Rob Chapman. It wanted a large area in southeastern Indiana that was surrounded by good transportation routes and where the population was fairly low.
“They found this area here that was in pretty good proximity to the munitions industry in the Midwest .... There was also rail service in the area.”
About 400 families “within the confines of the proving ground were told they had to leave and were only given a certain amount of time” to do so.
Some buildings, including a church, were moved, but “most structures on the property were demolished or used as targets, with the exception of the schoolhouse and the lodge.”
The Oakdale School, which is on the National Register of Historic Places, was built in 1869. Old Timbers Lodge was constructed between 1930-32 by the Alexander Thomson family.
For 50 years, “almost everything in the Army’s arsenal was tested here, small arms, grenades, bombs ... everything except nuclear and chemical weapons.”
Jefferson Proving Ground closed in 1995.
In 1996, the U.S. Fish and Wildlife Service began managing the wildlife resources on the proving ground. Big Oaks Refuge was established in June 2000 as an overlay national wildlife refuge through a 25-year real estate permit from the U.S. Army. As an overlay refuge, the Army retains ownership and the Fish and Wildlife Service manages the property as Big Oaks National Wildlife Refuge, according to https://www.fws.gov/refuge/Big_Oaks.
The refuge encompasses about 50,000 acres in three counties – Jefferson, Jennings and Ripley. “It is one of the largest (wildlife refuges) in our region,” the part-time ranger reveals.
The Indiana Air National Guard operates the Jefferson Range, which is located near the center of the former proving ground and is not designated as part of the refuge. “They do still drop dummy bombs (on the range), but nothing live,” the Batesville resident points out.
The 122nd Fighter Wing, Fort Wayne, with its A-10 aircraft and the 183rd Fighter Wing, Toledo, Ohio, with its F-16 aircraft are two of the groups that use the range.
There are large safety buffer areas that separate the range from the refuge’s public use areas. However, he cautions, “There are millions of rounds of unexploded ordnance that still exist (on refuge areas). That’s why the Army still owns the property. It would cost billions of dollars” to remove these munitions.
“Most of the open fields were impact areas. Many are closed to the public because of that .... Our staff doesn’t go into those areas either because of the types of ammunition that were tested.”
Chapman reveals another bit of history: Confederate Gen. John Hunt Morgan with 2,000 of his men raided through the area during the Civil War in July 1863. A stone marker shows the location where “local Union soldiers on leave captured three of the Morgan’s Raiders members.”
There are also reminders of the Army’s presence throughout the area. Metal posts for mounted cameras that captured what the various rounds looked like when they were tested are still intact as well as bunkers where military personnel could view charges being tested.
In addition, roads throughout the facility have names such as Shaped Charge Road, Machine Gun Road and Emergency Landing Field Road.
A metal bridge built in 1896 and several younger stone arch bridges are reminders of days of old.
The refuge staff includes four full-time and four part-time employees. Many staff members are wildland firefighters and are deployable.
“Our main function is to manage the natural resources .... Our primary management tool is prescribed burning.” Because of unexploded ordnances, “we can’t get out there .... Fire is one of the only things we have at our disposal.”
“Fire is a natural ecological process. We try to utilize it as a way to keep the biological integrity of these communities.”
At times, herbicides are also used.
The wildlife ecologist notes, “One of our management challenges is with invasive plant species. This is a big problem all across the U.S.
“We try to control those we have and keep those we don’t have out. Containment is how we control the ones that are here. We won’t be able to eradicate most of them, but we try to keep them from spreading.”
Wetlands, forests and grasslands are home to over 230 species of birds, 46 species of mammals, 25 species of amphibians and 18 species of reptiles.
The crawfish frog is one of the rare species that lives on the refuge. “We have one of the highest populations ... in the eastern United States.
“These frogs inhabit the burrows of crayfish ... They need shallow pools of water for reproduction.” On the prairies and grasslands of the central U.S., “they typically would use bison wallows,” natural topographical depressions that hold water and runoff.
“We don’t have a good understanding for why they (frogs) are here.” One possible reason is that the weapons tested by the Army made impact craters, which are similar to bison wallows. The frogs “could thrive in that environment. These are good surrogate pools for other frogs, too.”
“We do drain the wetlands because fish and frogs don’t get along well. Tadpoles are pretty good fish food.”
State endangered river otters were re-established at the refuge in the 1990s. They can be spotted any time of the year.
“We have one of the highest populations of Henslow’s sparrows in the eastern U.S.,” reports Chapman, who has a Bachelor of Science degree in wildlife science from Purdue University and a Master of Science degree in rangeland ecology from Oklahoma State University.
The grassland bird species is on the state endangered list.
Cerulean warblers, another state endangered species, can be found nesting high in the forest canopy.
“At least one bald eagle nests in the summer here.” He points out, “An eagle’s nest can weigh over a ton and be over 8 feet in diameter. The bird adds to it every year, and it gets bigger and bigger. At some point, the tree or the nest comes down and it (the bird) has to start over.”
The refuge is designated as a globally important bird area.
“There are (federally endangered) Indiana bats here.” There are caves, but they are not big enough for them to use as winter hibernation sites. They are usually found in large, dead trees with loose bark in the summer where they raise their young.
The bats are here in summer colonies. There is no overwintering of bats.
“A lot of our woods are flatwoods ... (and) many amphibian species are there.”
“We’re seeing a few more monarch butterflies coming through as they migrate to Mexico.”
“We have lots of beavers .... A couple beaver lakes provide a really neat wetlands community .... (However), if their dams cause issues, such as flooding the roads, we break them down.”
“I haven’t seen a lot of turkeys until recently,” the ranger says. On this day, many flocks were spotted. “Seeing groups of them like this is encouraging. They will travel in flocks this time of year, but come spring (mating season), they’ll fight.”
What is one of the big questions refuge staff get asked? “Is the bear still here?” This refers to a visitor that made its way on the property a few years ago.
“No, it is not still here. The bear left in spring 2017. It overwintered with us and went back home to Kentucky.”
Chapman says he enjoys working here because “I really like the diversity of habitats and wildlife here. I got into this field to get outside and enjoy natural resources.”