Antietam National Battlefield

Antietam National Battlefield

Geology

Springs and Seeps

There are many springs found within the park, most of which were historically used as the main water source for the farm families. On the Mumma, Roulette, Pry and Miller farms, the springs are covered by either by a stone or concrete springhouse.

Water may also sporadically emerge in fields, woods or rock outcrops. Not being contained by a springhouse, springs will naturally continue on as a stream. These streams are intermittent, meaning they are only present certain times of the year, if at all.

Rivers and Streams

Antietam Creek, one of Antietam National Battlefield's most significant natural features, is an important historical landmark, a tributary of the Potomac River, and a popular recreational spot. Nearly three miles of the creek and about one mile of its tributaries are located within the park's boundaries. About two miles south of the park, the creek's waters flow into the Potomac River, which becomes one of the largest tributaries of the Chesapeake Bay, the nation's largest and most productive estuary.

Cave/ Karst Systems

The geologic characteristics of the battlefield add to the complexity of natural resources management. Underlying the forests and fields is a bed of limestone, making up what is known as "karst topography". Karst features are formed when slightly acidic groundwater dissolves the soft stone, carving out spaces and cavities below the surface. This in turn creates not only springs and sinkholes, but also caves. Since these sensitive resources are directly linked to the area's groundwater, it is imperative that they be protected.

In response to management needs, the locations of known karst resources have been documented using a GPS receiver. Additionally, National Park Service water specialists have composed a scoping report that summarizes possible water management issues within the park. With this collection of information, future projects regarding karst systems can be implemented.

Flood Plains

Along Antietam Creek exists a section of floodplain forest that is critical to the creeks health. The forest serves as a riparian buffer and is mainly composed of red maple, silver maple, sycamore and black walnut.

Water Quality

The surface waters of Antietam Creek are generally characterized as being of good quality, although the area is showing some impacts from human activities. Primarily agricultural, wooded, or rural residential land users surround the creek and its tributaries within the battlefield; however, upstream municipalities and the neighboring town of Sharpsburg may also impact the quality of the park's water resources. These are problems that affect many natural areas in the face of intensive agricultural practices and increasing development.

Park resource managers have identified the following specific threats to the quality of Antietam's surface and groundwater resources:

1) Agricultural runoff or nutrients and erosion into park surface waters possibly causing eutrophication or sedimentation.

2) Groundwater contamination from old septic systems in Sharpsburg.

3) Sewage discharge from upstream municipalities.

4) Storm water runoff from the streets of Sharpsburg.

Many of the same hazards that threaten the waters of Antietam National Battlefield have led to a decline in the health of the Chesapeake Bay. One of the most serious threats is the excessive discharge of nutrients such as nitrogen and phosphorus into the tributaries of the Bay, resulting in the eutrophication of many waterways. This process depletes water of oxygen, which in turn kills fish and other plants and animals. The National Park Service joined the Chesapeake Bay Program (a regional agreement to reduce nitrogen and phosphorus levels entering the Bay) in 1994 with a commitment to aid in the creation of streamside riparian buffer zones throughout these tributaries. These buffers are vegetated areas that stretch 35 feet or more from the water's edge and may be fenced off to prevent livestock from entering the water. Riparian buffers will help achieve both the nutrient reduction and the habitat restoration goals put in place by the program. In addition to the establishment of these zones, park staff also works with cooperating farmers on agricultural nutrient management issues. As a means of examining the effects of these programs, Antietam's Natural Resources Division has initiated a water quality-monitoring plan. Thirteen times a year, several water quality parameters are measured at six different locations within the park. Park staff record the water temperature, depth, pH, dissolved oxygen content, and nitrogen and phosphorus levels for each of these sites. Using computer software, data is recorded and analyzed to determine impacts of park activities on water quality. In an effort to contribute to the environmental awareness of today's youth, a program known as "Water Watchers" has been established. For only a few days each spring and fall, students from area schools, elementary to high school, are invited to participate in this three-hour program. Park rangers discuss with the students the importance of clean water and viable aquatic ecosystems. Then, in groups of four, the children conduct basic water quality tests in either Antietam Creek or Sharpsburg Creek here at the battlefield. They calculate and record not only physical parameters such as water depth and temperature but also chemical properties like pH and dissolved oxygen content. The third characteristic of water quality that Water Watcher participants examine is the type of macroinvertebrate species that inhabit the creek. These animals, mostly aquatic larval insects and worms, live under rocks of the creek bed and in the earth itself. Students donning waders and carrying nets, then stand in the water and do the "benthos two-step," where they twist and kick their feet to loosen the creek mud and dislodge the aquatic inhabitants. Once their nets are full, they return to the stream bank to sort and identify the creatures they caught. Based on the types of animals they have found, students can determine the health of the creek for that moment in time. Class averages for the water tests are then calculated and recorded for long-term trend monitoring. By introducing children to the importance of water protection through its Water Watchers program, the staff of Antietam National Battlefield hopes to foster an environmental consciousness in the youth of today that will accompany them well into the future.

Natural Features & Ecosystems

Anyone visiting the park will realize that this historic site commemorating the battle of Antietam is not only significant because of its cultural value, but also its natural one.

The park lies on a bed of limestone, lending it to a variety of geologic features including karst systems, springs and seeps. This also provides a viable foundation for the very rich oak/hickory forest known as the Snavely Woods. Running through the woods is Antietam Creek, the body of water from which the battle received it's name.

Efforts are currently underway to inventory and monitor the water resources, forests communities, plants, animals and soils that comprise Antietam's historic landscape.

Lakes and Ponds

The only pond found within the park boundary is located on the Roulette farm. It is fed by a spring that begins on the Mumma farm and runs east to this small wetland. Home to a few small-mouth bass and catfish, the pond also provides a habitat for various reptiles and amphibians.

Soils

Soil is a three-dimensional body consisting of organic matter, mineral matter, air and water. Essentially, it is formed by rock weathering over long periods of time. Most soil found on the battlefield can be classified as the Hagerstown Series (soils are named after the area in which they are first discovered). Characteristics of every soil depend on multiple factors. First is the nature of the geologic material from which the soil is formed, or parent rock. This determines the texture and mineral content of the soil. Most of Antietam lies on a limestone foundation with some shale, sandstone, siltstone and dolomite. Second is relief (the lay of the land), which at Antietam consists of broad, rolling valleys. Relief affects drainage, aeration, runoff, erosion and exposure to sun and wind. The geology here causes it to be highly susceptible to these elements, resulting in soil that is classified as highly or potentially highly erodible. The third factor is climate, influencing the nature and extent of weathering. The climate of Washington County is the humid-temperate, continental type. Researchers believe, based on soil characteristics, that this climate had an impact on the formation of the soil since many of the area soils are acidic and strongly leached. The farm fields in the park are sprinkled with lime from time to time to neutralize the acid. Fourth, plant and animal life in and on the soil are an influential factor. The vegetation is generally responsible for the amount of nutrients. Burrowing animals, such as earthworms, cicadas, and others, help to keep the soil open and release nutrients for plant food. Since most of the battlefield has been used as farmland for well over a century, human activities have also had a significant impact on the surface soil layer. This leads into the final factor influencing soil characteristics, which is time. Over the years, records of the area document activities such as clearing forests, plowing land, adding fertilizers and moving soil materials from place to place. Each of these factors can significantly impact the make up of the soil and its fertility. It is critical for managers to understand and maintain soil integrity as it supports the elements of Antietam's cultural landscape.