The Claggett Retreat site (18FR25) describes a Late Woodland hamlet located on the north bank of the Monocacy River just east of the present town of Buckeystown, in Frederick County, Maryland.  Diagnostic ceramic styles, a radiocarbon date and the pattern of features at the Claggett Retreats site place it culturally within the Mason Island Complex, the earliest of three Late Woodland cultural manifestations identified in the Middle Potomac Valley.

Archaeological Investigations

The Claggett Retreat site was located by avocational archaeologist Calvin Swomley in 1964.  The site was officially recorded by Spencer Geasey in 1970.   Formal investigations at the Claggett Retreat site began with two visits to the site as part of the Monocacy River Regional Survey between 1978 and 1982.  The Archaeological Society of Maryland (ASM) in cooperation with the Maryland Historical Trust (MHT) and the American University Department of Anthropology  Potomac River Archaeological Survey (PRAS) sponsored excavations at Claggett Retreat in 2007 and 2008.  These field sessions served as the ASM's Tyler Bastian 36th and 37th Annual Field Sessions in Archaeology. 

The Claggett Retreat site is the only single component Mason Island site that has been identified in the Middle Potomac Valley.  The AMS/MHT/PRAS excavations in 2008 and 2009 offered the opportunity to systematically collect and analyze plant macro-remains and to make a significant contribution to better understanding Native American subsistence practices and environmetal conditions in the Potomac River Valley during the early Late Woodland period.  Soil samples for flotation processing were collected from seven cultural features excavated at the Claggett Retreat site. Samples were placed in storage at American University awaiting analysis.  In 2009, the Archaeological Society of Maryland committed funds to support the processing and study of the Claggett Retreat site archeobotanical collection. 

Archeobotanical Studies              

Seven archaeological soil samples from seven cultural features excavated at the Claggett Retreat site (126.5 liters) were analyzed by Justine McKnight in 2010.   Samples were flotation processed in a Flot-tech machine, resulting in the recovery of 75.545 grams of carbonized plant macro-remains (a mean average of 0.587 grams per liter of floted soil).  The recovered archeobotanical remains were both abundant and diverse, and the condition of recovered organic remains was excellent. A wide variety of economically important plants were represented in the analyzed assemblage:  These include a predominance of wood charcoal (dominated by hickory and white oak species); maize; sunflower; three genera of native mast; wild fruit, grain and ruderal seed; and miscellaneous plant materials including fungi, and amorphous carbon.  In addition, non-carbonized seeds were present in 100%  percent of the analyzed samples. 

Data generated from the study of seven flotation samples collected during two seasons of field excavation at the Claggett Retreat site (18FR25) make an important contribution to our understanding of Mason Island Complex plant use in the Middle Potomac Valley.  The site botanical assemblage offers a wealth of data regarding subsistence and land use during the early Late Woodland period.   It is significant that while the Mason Island occupants of the Claggett Retreat site successfully farmed maize and sunflower, they also relied heavily on the seasonally-predictable wild fare available from a rich local forest environment.  Importantly, the new data from Claggett Retreat corroborate the rich archeobotanical dataset generated from Mason Island features at the Barton Site (18AG3).  Together, the evidence from these two related sites builds a clearer picture of the cultural traditions associated with Mason Island ethnobotany. 


Lab Number

Measured Age

Cal 2 Sigma low

Cal Median Probability

Cal 2 Sigma

Feature 251

Beta 275419

400+/-40 BP




As part of a cultigen dating project supported by the Maryland Archaeological Conservation Laboratory in 2009/2010, a maize cupule fragments from Feature 34 (a shallow basin) at Claggett Retreat were selected for direct radiocarbon dating using the AMS technique. The sample produced an uncalibrated radiocarbon date of 400 +/40 BP/AD1550.   Click here to see graphic representation.


Dent, Richard J.
  In press-Report on Archaeological Investigations at the Claggett Retreat Site(18FR25), Frederick County, MD.
McKnight, Justine

Report on The Analysis of Flotation-recovered Archeobotanical Remains from the Claggett Retreat Site (18FR25), Frederick County, Maryland.  Report submitted to the Potomac River Archaeological Survey, Department of Anthropology, American University. February 3, 2010.

McKnight, Justine W.
2010 Analysis of Flotation-recovered Archeobotanical Remains from the Claggett Retreat Site (18FR25), Frederick County, Maryland. Maryland Archaeology, Volume 46; Numbers 1 & 2; pp 38-46.

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