Encountering The Cragg Cabin:  Preservation And A Sense Of The Past
by Hal Hassen, IDNR Archaeologist

 When we enter our homes from the outside we usually do not think of the past.  We are surrounded by modern technology and conveniences.  Cross the threshold of Lincoln’s home and we think not of the present but of the past.    The Cragg cabin located at Goose Lake Prairie State Natural Area similarly evokes thoughts of the past.

     The Cragg cabin was originally constructed in the 1830’s and stood for 100 years before it was moved and underwent extensive repairs.  Over the years the cabin has undergone additional rebuilding phases and was eventually moved to its current location at the state park.  Does the cabin resemble the original Cragg cabin in all its details constructed over 170 years ago?  It probably does not.  However, is an accurate representation of the physical qualities of the cabin most important or is the message conveyed by the cabin more significant.   For me, the past is not a place; it is a state of mind.

Absent a time machine, we can never really live in the past.  We are, however, interested in the past.  The reasons are numerous but for many of us there is interest in comparing what life was like in the past to how we live today.  This includes technology and social customs and beliefs.  Lincoln’s home in Springfield sits on its original lot and is surrounded by several houses that would have been present when the Lincolns lived at their house.  However, when visitors stand in the street outside they stand on a well groomed gravel road and easily see many of the large commercial buildings that make up the surrounding neighborhood.   So while much of the original context and fabric of the buildings remain intact, there have still been many changes from how the
neighborhood and the house looked in the mid-1800s.  Historic rehabilitation and reconstruction is tricky.  One always tries to maintain as much of the original look as possible.  Unfortunately many factors can make it difficult to adhere to 100 percent historical accuracy.

When the Cragg cabin was again rebuilt and moved to its current location, the participants meant to create something that would have provided the visitor with a sense of the past.  Despite some problems with its appearances, the Cragg cabin still conveys a strong sense of the past for the visitor.  Walking into the Cragg cabin or even seeing it from afar, the visitor is immediately presented with thoughts about the past.   Comparisons are made between old and new technology.  Comforts we take for granted are even more relished when faced with the harsher conditions which probably existed based on the timber framing illustrated in the Cragg cabin.

As the archaeologist for the Illinois Department of Natural Resources it is my responsibility to ensure that the Department protects it’s archaeological sites and significant standing structures so they are preserved for the future.  Once protected, a structure can be interpreted for the public.  Good interpretation will then enhance visitor appreciation for the resource.  A well informed public with appreciation for historic resources will inevitability lead to increase protection and broader public support for historic preservation.

Public involvement in moving and reconstructing the Cragg cabin is particularly rewarding when younger people are involved.    The participants take with them an appreciation for historic preservation, while presenting the visitor a window into the past.  The region surrounding the Goose Lake Prairie State Natural Area was settled later than other areas in Illinois.  Nonetheless the conditions faced by those first settlers were harsh and difficult.  Building materials were gleaned from the natural environment and houses were built using skills and techniques less common today.    There is no question that a visitor to the Cragg cabin will come away with some sense that life was different 170 years ago.  In the end I think that is what is most important. 

Reflecting upon the past and what it means can be triggered by old photographs, stories, or the physical presence of old buildings.  The Cragg cabin speaks to us about early settlers and  lost technologies. 

See Our history page for more information on the Cragg Cabin.

Posted June 29, 2011 from the Tallgrass Journal Summer, 2011 page 1,3.

 Fire on the Prairie by Kim Roman

Fire is an essential component of the tallgrass prairie; it keeps invading trees and shrubs at bay, controls non-native species, makes nutrients more readily available to prairie plants, and promotes diversity in both the prairie plant community and wildlife habitat structure.  Fire was a natural component of the pre-settlement landscape of Illinois, and Goose Lake Prairie is almost entirely dependent upon it.  Without fire, Goose Lake Prairie would become an impenetrable woody thicket in a matter of a few decades.

Pulling off a controlled burn at Goose Lake Prairie is no small feat.  This site is one of the trickiest in the state, due to its sheer size and fuel type (burn managers refer to a site’s combustible vegetation as “fuel”).  Tallgrass prairie fuels can easily produce flame heights of 40 feet and taller.  An experienced crew of certified burn managers is required to safely conduct a prescribed fire at Goose Lake Prairie.

The fire boss assembles a burn crew from the region, usually comprised of 8-15 individuals (depending on the complexity of the burn), all equipped with fire-resistant Nomex suits and wildland fire-fighting equipment.  There are a minimum of 4 all-terrain vehicles, each rigged with 50 gallons of water, 200 feet of hose, and a high-pressure pump.  Hand tools such as drip torches,  rakes, flappers, and 5-gallon backpack sprayers are also required on each fire.  A back-up water supply of several hundreds of gallons is also on site.

Goose Lake Prairie is divided into multiple burn units easily denoted by the mown strips.  Some units are only 40 acres, whereas other units may be over 600 acres in size.  Most burn managers do not burn 100% of the natural area in one season; there should always be unburned vegetation to serve as a refuge for insects and other wildlife.  It is also desirable to have diversity in the habitat structure of a large grassland to accommodate the variety of nesting grassland birds.  Some birds, like the Henslow’s Sparrow, prefer a thick accumulation of grasses, and other birds such as the Grasshopper Sparrow, are more abundant after a recent burn.  The site’s biologists rotate burn units, and usually try to burn a couple units each year at larger sites, as  weather permits.

The burn unit is defined by its firebreaks, which can be natural features or man-made.  At Goose Lake Prairie, the burn units are designed using mowed trails, roads, and bodies of water.  The burn crew begins at the downwind side of the burn unit by lighting the fuel (dried prairie vegetation) at the edge of the unit immediately adjacent to a mowed trail or road.  The fire spreads in all directions, but at varying rates, depending on wind speed and direction.  The rapidly spreading downwind side of the fire is extinguished by spraying water and snuffing it out with hand tools, or simply when the fire reaches a firebreak with no fuels, like a road or open water.  The upwind side of the fire is allowed to slowly creep into the wind, towards the middle of the burn unit (know as a “back-fire”).  The fire boss evaluates the behavior of the fire while it is still small and easy to extinguish.  If the fire is behaving as expected under the weather conditions and fuel type, the crew splits into two teams, heading in opposite directions.  Each team uses drip torches to light along the firebreak, working with the wind and extinguishing the downwind flames along the firebreak.  The fire within the unit is allowed to continue creeping upwind so  the firebreak is widened by creating a “black line” of burned fuel.  This is the most critical and time consuming element of conducting a controlled burn.

The fire teams are in constant communication with each other while lighting the back-fire, and regularly monitor the weather.  Temperature, humidity, wind speed, and wind direction can vary throughout the day and greatly influence fire behavior.   The teams continue lighting along the edges of the fire unit, almost circling the unit, until it is time to make the turn where the wind will carry the head-fire.  Both teams hold steady while the fire boss evaluates the width of the black line.  As a general rule of thumb, the black line at the downwind side of the burn unit should be 3 times as wide as the tallest expected flame height.  If there is plenty of black line, one or both of the teams are given the go-ahead to completely circle the unit and light the head-fire.  As the two teams meet up again, flames roll over the prairie, consuming nearly everything in their path.  The fire extinguishes itself when the head-fire is pushed by the wind into the back-fire, where there is no more fuel left to burn.

This past fall was an exceptional season for conducting prescribed fire at Goose Lake Prairie (among other sites within the region).  The weather was unusually warm and dry, with favorable winds keeping smoke off Pine Bluff Road.  Two burns were conducted; both immediately north of Pine Bluff Road, and on either side of Jugtown Road.  The western unit went exactly as planned.  The eastern unit however, kept the burn crew working into the night.

While back-burning and widening out the black line through a part of the east unit which is dominated by the non-native common reed (Phragmites australis), the fire had jumped the line.  Phragmites is one of the most invasive plant species in our wetlands, and it can grow up to 10 feet tall.  When dense stands of it ignite, flame heights can easily get up to 50 feet.  During the back-burning portion of this prescribed fire, the super-heated air column above the burning Phragmites pushed a lit ember up and outside the burn unit.

The burn crew quickly implemented the back-up plan which was discussed before the fire was even lit.  They would allow any escaped fire to burn until it reached the open water of the wetlands located downwind.  The wind was pushing the escaped head-fire straight for the wetlands, and fire crews had to contain only the flanking-fire, with flame heights of about 3-6 feet.  When the controllable flanking-fire met up with the open water wetlands, the escaped fire would be extinguished.  However, the fire boss decided additional resources were needed and contacted two local fire departments.  Coal City and Morris Fire Departments were invaluable in providing the IDNR fire crew with extra water used in controlling the escaped fire, staging additional wildfire equipment, and keeping travel on Pine Bluff Road safe (some drivers have a tendency to watch a fire instead of the road!).

After gaining control of the escaped fire, the burn crew needed to complete the prescribed fire within the rest of the original unit.  The back-burning and widening the black line still needed to be completed.  This slow process was made even slower due to cooling temperatures and rising humidity.  The head-fire was eventually lit around 7 pm, and final mop-up wasn’t completed until after midnight.

A fire at Goose Lake Prairie is always an impressive sight.  Witnessing Goose Lake Prairie ablaze and glowing into the night was even more of an awe-inspiring spectacle.

 This is not the first time Kim Roman has written for the Tallgrass Journal.  We welcome her articles.  Kim is employed by the Illinois Nature Preserves Commission.

Posted April 15, 2011from the Spring 2011 Tallgrass Journal. 

Panicum virgatum L., or switchgrass, is a warm-season perennial grass species native to much of North America.  Historically, it was a major component of tallgrass prairie ecosystems, although wild populations have declined in recent decades due to the loss of most of our native prairie range.  Switchgrass can still be found in native prairie remnants, which are distinguished from other prairie systems by the lack of human disturbance or length of time since disturbance, and are presumed to contain the descendents of the once vast tallgrass communities.  Over the last several decades, however, switchgrass has been selectively bred by the USDA and others for different purposes, most recently for use as a biofuel, and mass plantings are seemingly imminent in several central and Midwestern states. The potential impact of biofuel cultivars on wild relatives is, as yet, unknown.

Switchgrass is naturally a range grass and has been fed upon by ruminants for centuries, but it became a focus of study for use as a forage crop by scientists in the early 1970’s.  Backed by the USDA, agronomists selected individual switchgrass plants that possessed desirable traits, such as increased biomass, high digestibility, or better winter survival, perhaps reducing genetic variability and increasing homogeneity, compared to the wild forbears.  Over the years, the USDA has released several switchgrass cultivars, each selected and/or bred for specific traits.

In the late 1980’s, switchgrass became one of several species of interest as a potential biofuel crop (biofuels, whether burned or converted to ethanol, are an attractive alternative to conventional fossil fuels because they are renewable and have the potential to be more economical and environmentally friendly than conventional fuels).  By the early 1990’s, researchers at the USDA and other groups, like Ceres, Inc., had determined that switchgrass had great potential as a biofuel and their research efforts, funded in large part by the Department of Energy, continue to look for ways to make ethanol conversion efficient and economical.  Traits that were attractive in forage switchgrass are now being selected to a greater extent in biofuel switchgrass, which could further reduce genetic variability of the cultivar.  Added to this is the fact that a few research groups are attempting to genetically modify switchgrass by inserting foreign genes, or “transgenes,” into the plant’s genome in order to increase the speed with which switchgrass becomes biofuel-ready.  Genetic modification of switchgrass is not currently practiced by the USDA, who oversees the commercial release of cultivars.  However, non-transgenic biofuel switchgrass appears to be on the verge of widespread plantings across several U.S. states.

While the creation of a cleaner, more economical fuel is by no means objectionable per se, there is a lack of empirical scientific research about general switchgrass ecology, and virtually nothing is known about the potential impact of switchgrass cultivars on wild relatives.  Some researchers and conservation groups have expressed concern that cultivars could escape cultivation and become a weedy invader or cross with wild relatives, producing hybrids that could dilute the native gene pool.  Others believe that since forage cultivars were derived from wild ancestors and breeding cycles take years to complete, cultivars are not that far removed genetically from wild counterparts.  However, there are very few scientific studies that have addressed these questions directly.

Some ecologists have risen to the challenge and are trying to keep pace with agronomic research and development by addressing the more urgent questions related to switchgrass ecology.  Researchers at universities such as Ohio State and Iowa State, for example, are collaborating to tackle some of these pressing questions.  Hopefully soon, we will have good, empirical data that will shed light on any potential risks associated with biofuel cultivars, so we can make informed decisions about whether and where to plant biofuel switchgrass.

Several remnant prairie patches exist in and around Grundy County, Illinois, and wild switchgrass populations can be found at Goose Lake Prairie, Midewin National Tallgrass Prairie, Des Plaines Conservation Area, Grant Creek Nature Preserve, and Hitt’s Siding Nature Preserve.  While the switchgrass populations located in these prairie remnants are not large, they are nevertheless an important component of the remnant prairie community.  Since we don’t really know what, if anything, will happen to wild populations when biofuel types are introduced, new research is vital to our increased understanding of this species.  

Amy L. Campbell, M.S. is a Ph.D. student studying plant ecology with Dr. Allison Snow at The Ohio State University in Columbus, Ohio.  Amy has three main goals: to determine the potential for gene flow between cultivated and wild switchgrass populations, to investigate genetic similarity between the two groups, and to examine fitness-related traits as a measure of the potential invasiveness of cultivars in relation to wild counterparts.  It is important to Amy’s work that she sample switchgrass individuals from truly wild populations (as opposed to restored areas).

Luckily, Goose Lake State Park has a few true remnant prairie patches, which are becoming increasingly rare and, thus, harder to find.  In 2009 and 2010, with the help of prairie specialist Art Rohr, Amy visited Goose Lake Prairie and collected leaf tissue and seeds from switchgrass individuals growing in the remnant prairie patches.  She will use these samples in her research, and hopefully the information Amy discovers can be used as an important jumping-off point for future ecological studies about biofuel switchgrass.  
                                                                                                 (Excerpt from the January (Winter) Tallgrass Journal, 2011.)

The Illinois Prairie:  Feats of Clay.

Submitted by Chris Rollins

Our special article  on Illinois Prairie  History this month was written by Christopher Rollins. Chris is in his third year as Regional Land Manager,  IDNR Region 2 and frequents Goose Lake Prairie SNA very often.  Chris holds a double major in Animal Science; and Political Science and a Bachelor of Arts -Board of Governors’ Degree from Western Illinois University.

Sunmer 2009 Issue of the Tallgrass Journal.

Submitted by Chris Rollins

Our special article  on Illinois Prairie  History this month was written by Christopher Rollins. Chris is in his third year as Regional Land Manager,  IDNR Region 2 and frequents Goose Lake Prairie SNA very often.  Chris holds a double major in Animal Science; and Political Science and a Bachelor of Arts -Board of Governors’ Degree from Western Illinois University.