Prehistoric Landscapes of the Nation's Capital: The Whitehurst Freeway Sites

The Whitehurst Freeway project area. NPS photo.

The excavations

In 1996 and 1997, Parsons Engineering Science excavated the Whitehurst Freeway corridor in Washington, D.C., for the city's Department of Public Works, under an Archaeological Resources Protection Act permit from the National Park Service. At the eastern end of the roadway, near where Rock Creek drains into the Potomac River, they found both prehistoric and historic remains — among them the Peter House and Whitehurst West sites.

The Peter House site

Foundations of 18th- and 19th-century houses had been built straight over intact prehistoric deposits. Under the sidewalk north of the houses ran a gully, filled in late prehistory with layered, charcoal-rich deposits: fire-cracked rock, flakes from making stone tools, and pieces of broken pottery (sherds) — enough to show the surface was open and stable for a long time.

Prehistoric ceramics from the Whitehurst Freeway sites. NPS photo.

• Dates: artifacts ranged from Middle Archaic projectile points (6500–3000 B.C.) to Late Woodland points and ceramics (900–1600 A.D.), most of them Middle and Late Woodland (about 500 B.C. to 1600 A.D.). The deposits built up partly from trash thrown down from a large site upslope.
• Hearths: two intact hearths from the early Late Woodland held fire-cracked rock and sherds; food residue charred inside some sherds dated to about 1100 A.D.
• Plants: bedstraw, pokeweed and wild grape, all with known prehistoric food and medicinal uses.
• Radiocarbon: the surrounding deposit dated to 970–1090 A.D., and its lowest levels to 260 B.C.–180 A.D. — placing the main occupations in the Middle to early Late Woodland.

Hearths at the Peter House site. NPS photo.

Whitehurst West

This site lay on a terrace beside Rock Creek, west of the Rock Creek Parkway — now about 45 meters (148 ft) from the stream bank and 2 meters (7 ft) above high tide.

• Bottom: a natural gravel bar on Ice Age river deposits, perhaps exposed late in the Late Archaic — one radiocarbon date is 2650 B.C.
• Feature 502: a thick deposit of ceramics, stone tools, fire-cracked rock, cobbles, charcoal and gravel from a Middle Woodland occupation, dated to 770–990 A.D. The layer above dated to 1210–1260 A.D., and the uppermost to 1640 A.D. More than 4.25 meters (14 ft) of historic fill lay on top.
• Food: small pieces of burned animal bone, and pokeweed, hickory nut, walnut, raspberry and blackberry remains. Residues on sherds show people processing grass seed and a tuber related to the potato. The spread of artifacts suggested the deposit's layout was partly preserved.

Levanna triangular blades. NPS photo.

Why here

The sites sit near the mouth of Rock Creek, below the Great Falls of the Potomac — the fall line, which mattered to prehistoric people as:

1. a meeting point between different groups or cultures;
2. a place to control access to critical seasonal resources;
3. a narrow point on a regional trade route.

In late winter and early spring, anadromous fish such as herring swim from the Atlantic and Chesapeake Bay to spawn in fresh water. The runs below the Great Falls gave Woodland people protein in the leanest months. The Peter House deposits of 970–1090 A.D. point to a large settlement upslope, and Feature 502 may be refuse from an early Late Woodland village placed to take advantage of the fish runs.

Digging under the city

Intact deposits lay beneath 3 to 17 feet of historic fill. Filling along Rock Creek began in the first quarter of the nineteenth century, when digging the Chesapeake and Ohio Canal supplied fill to reclaim swampy ground — the nearby Watergate stands on what were 18th-century mudflats — and continued into the twentieth.

• Removing fill: a backhoe took off the fill — less than 3 feet near K Street, 14 feet over Feature 502 — and hand excavation began at intact deposits.
• Safety: the digs met OSHA standards with a 1.5:1 slope, benching or shoring. Because Whitehurst West was 14 feet deep and hemmed in by the Rock Creek Parkway and a jogging path, shoring was built.
• Water and cold: dug in the winter of 1996–1997, beside the creek in a wet season, the site needed well points to lower the water table, and a shelter so archeologists could keep working below freezing.

Wooden shoring and construction of the temporary shelter. NPS photo.

The Park Service notes that this content is being reviewed with Tribal representatives, to make sure the voices and perspectives of associated Tribes are included.

Sources

Based on "Prehistoric Landscapes of the Nation's Capital," Rock Creek Park, National Park Service; a work of the United States government in the public domain.