Sawmill Hollow Interpretive Trail
Jackson-Washington State Forest
Welcome to Jackson-Washington State Forest and the Sawmill Hollow Interpretive Trail. The trail will give you the opportunity to observe many of the multiple-use resource management techniques used on the state forest. It will also take you back in time to the days before this forest became public land, and give a brief history of the state forest itself.
Allow at least 2 hours to hike the trail and look at each stop. Trail stops are marked with natural wood posts with yellow numbers on top and interpretive decals on the front.
For more information about the topics covered along the trail, or to learn more about Jackson-Washington State Forest, please contact the forest office:
Phone: (812) 358-2160
or call the Division of Forestry office at (317) 232-4105
Trees and Features on the Interpretive Trail
- Erosion. Before the state acquired this area in the 1930s, the land around this stop was either farmland or pasture. The steep slopes and lack of erosion control caused the slopes to become rutted with deep gullies, which are visible here. After the state purchased the property trees were planted to help stabilize the soil.
- Fencing. As you hike, you may notice remnants of old fences running into the centers of trees. Early settlers often nailed their fences to trees along property lines. As the trees grew, they grew right over the attached fencing.
- Pine Trees. Naturally occurring pine trees are very rare in this part of Indiana. Almost all the pine trees on Jackson-Washington were planted for erosion control. Pine and black locust trees were selected to plant because they thrived on the poor, eroded soil. The pines and locust trees have done their job well and are being replaced naturally by native trees.
- Genetic Tree Research. The trees planted on the other side of the stream are butternuts, or white walnuts. These trees are being tested to determine if they are resistant to a disease called butternut canker, which has seriously decreased the number of butternut trees across the state. Trees that are resistant to canker will be used as a source of seed for future generations of seedlings.
- Seed Production. To assure the nearby state tree nursery has an available supply of acorns from high quality white oak trees, the state forest developed this seed production area in 1984. Competing trees were removed from around these seed producers, so the trees are encouraged to produce more seed that is easier to collect than if the trees were in a crowded forest.
- Past Timber Harvest. An "improvement harvest" was done in this area in 1983 to remove defective trees and reduce the number of trees per acre. A total of 131,586 board feet of timber was removed over a 57-acre area during this harvest, a volume of lumber equivalent to a board 1' wide, 1" thick and 25 miles long! Notice the number of new trees that have grown where the trees were removed.
- Regeneration Opening. Openings like this one duplicate natural openings created by storms or mortality. These small openings help establish a new, more vigorous stand of trees. Forty-six trees were removed form this 1.4 acre opening by hand in 1997, allowing the remaining trees more room to grow. Walk down the path and look into the new forest developing in this regeneration opening!
- Harvest Area. Selecting trees to harvest is like thinning plants in a garden to allow remaining plants the sunlight, nutrients and space to grow properly. The area around this stop has been marked as if it was to be harvested. The trees with yellow bands would be the ones removed. Tree #1 (chestnut oak) was marked to release 2 white oak near it. Tree #2 (chestnut oak) was marked because it is mature and will release 2 white oaks and 2 chestnut oaks. Tree #4 (chestnut oak) was marked because it is low quality and will release 2 chestnut oaks and 1 white oak. Tree #5 (white oak) was marked because it is a low quality stem and will release 3 other white oaks.
*The interpretive trail is joined shortly after this stop by a trail developed in cooperation with nearby Camp Pyoca. Please stay on the marked trail and do not explore the private property of Camp Pyoca!
- The Rest of the Forest. Enjoy a rest on the bench since you're at the halfway point on the trail. Notice that there is more to the forest than the trees. Enjoy the "rest of the forest" in the smaller plants, lichens and insects, which are often overlooked when we spend all our time concentrating on the trees.
- Wetlands. Wetlands are natural sponges that store runoff and purify water. They provide flood protection and erosion control. Acre for acre, wetlands support more wildlife than any other habitat. Protecting wetlands is critical. Notice the different plants, birds and insects in this area that were no present in the woods.
- Intermittent Stream. Streams such as this one are called intermittent streams because they don't always contain flowing water. During wet seasons and heavy downpours, the streams will be full or even overflowing. But most of the time, the water flowing through the drainage system is below the surface. Intermittent stream beds are often the home of their own diverse ecosystems.
- Civilian Conservation Corps (CCC). The steps you walked up, the foundations located along the trail, and the standing chimneys are part of the CCC camp that was located here in the 1930s. The CCC was a federally-sponsored program during the Great Depression that provided jobs for the unemployed and addressed some of the country's conservation needs. Many CCC structures still stand in the main campground area and in other DNR properties throughout the state.
- CCC Roads. The road you are walking on was constructed by the CCC. The road was built up from the surrounding ground using teams of horses and slip-scoops. The only source of gravel was from the local creeks, so the crew dug gravel from the creek and spread it along the road as a base to keep it from getting muddy. Creek gravel lasted so long that many of the roads where it was used are still in good shape.
- Wildlife Opening. This wildlife opening is a demonstration and is smaller than what is normally created. Young birds will use this area to eat bugs and tender blades of grass. Deer will also graze here. The grass that has been planted is orchard grass, which grows tall to provide cover for young animals while they are in the opening. Stubby sumac trees left in the center of this opening provide both cover and a food source in late fall and winter.
- Young Tuliptree Stand. Directly behind this site post is a group of mostly one species of tree. This stand of tuliptrees (also know as yellow poplar) developed this way because sun-loving tuliptrees took over an abandoned field. The central hardwood forest is amazingly resilient; you are standing in what was probably a cornfield in 1920.
- Logging Roads. This portion of the trail is a road used by the area's original settlers. Many of these old roads have been maintained as logging roads. Logging roads and skid trails, besides providing access for logging, provide access for recreational use and fire protection and grow grassy vegetation for wildlife food and cover. Most modern logging roads on the state forests are built on these early pioneer roads.
- TSI Demonstration. TSI stands for Timber Stand improvement. This management activity is usually done after a harvest and/or in a very young stand that has too many trees for proper growth. TSI is done to remove damaged or low-quality trees and to improve growth on better quality trees. The trees with red paint on them would be deadened by making a cut through the bark entirely around the stem. This technique is know as "girdling". Tree #1, marked in orange, is suppressed and a low-value tree because of the curve in the trunk. By removing orange tree #1, white #1 and #9 will benefit from the extra sunlight. By removing orange #3, white trees #3, #4, and #8 are given more sunlight and room. Look at the remaining trees and see if you can tell why they are marked to be removed and why removing them will help the remaining trees in white.
- No Hunting Zones. Hunting is allowed on state forests as a recreational activity and as a management tool. Hunting and other outdoor recreation activities are part of the multiple use philosophy of state forests. To ensure the safety of forest visitors, certain areas are designated as No Hunting Zones.
- Forest Monitoring Plots. To understand the changes that take place in a forest over long periods of time, it is necessary to establish permanent monitoring plots which can be returned to every few years. This is a representation of what a forest monitoring plot may look like. The plot center is located using a small metal pin (here a painted piece of rebar) which is flush with the ground. Then each tree within a given distance form the plot center is marked for identification. A forester collects information such as tree species, diameter, height, tree grade and health. A map is made showing the exact location of each tree, so the same tree can be revisited and measured again. One such forest monitoring system is known as the Forest Inventory Analysis, or FIA, which is conducted by the U.S. Forest Service in each state every 10 years. The most recent FIA survey of Indiana's forest lands was conducted in 1997.
- Forest Health Monitoring. The dark bands and triangular boxes attached to the trees are used to trap insects that defoliate trees in the forest. Both the bands and boxes catch gypsy moths. The bands are covered with a sticky substance that traps the caterpillars, or "loopers." The box is a gypsy moth trap. It contains the scent of the female moth, called a pheromone. The male moth flies to the pheromone and gets caught in the sticky trap. The traps are placed across Indiana every year to determine where gypsy moths are in the state. In other states like Michigan and Pennsylvania, gypsy moths have defoliated and killed up to 20% of the forest! The poster shows the life cycle and discusses the history of the gypsy moth.