Workers digging at stone piers of an 1890s-era bridge came up with an artifact dating back even earlier.

Joseph Yodis of Shenandoah, project inspector-in-charge for the Pennsylvania Department of Transportation, said workers excavated a large, signed rock buried in the river bed beneath the center arch of the East Broad Street bridge, Route 209.

"We got lucky because we only excavated 6 feet wide. We dug a trench about 4 feet. It was down between 2 and 3 feet," Yodis said. "It wasn't connected, but was butted up against the bridge.

Workers believe the rock was place at streambed level at one time. However, later flooding and the forces of nature eventually buried the rock under dirt and river silt over subsequent years.

But what makes the find special is the engraving.

Closer examination by Yodis revealed heavy, ornate letters carved in the half-ton boulder.

Among the messages, "J.C. Springer, Tues. April 23, 1878," flanked by initials C.E. and A.R., along with initials W.S. at the bottom.

Recognizing it as a piece of history, Yodis extracted the rock and transported it to a nearby PennDOT field office.

Tamaqua historians believe the rock was part of the foundation of an earlier wooden bridge, perhaps a covered bridge, that once existed at that location and appears on 1880s Sanborn maps.

"It measures about 5 feet long, 3 feet wide and 2 feet high," said Dale Freudenberger, president, Tamaqua Historical Society. "Those letters appear to be hand chiseled."

Quick research reveals that many J. Springers lived in the community in the 1800s.

John Springer was a member of the 48th Pennsylvania Regiment and died in the Civil War. Another, Jesse, was trustee of the Methodist Episcopal Church in 1881, and still another, Joseph, operated a river sawmill 6 miles below town. However, the business was wiped out during the Great Flood of 1850.

The stone will be donated to the historical society for preservation.

The present East Broad Street bridge over the Little Schuylkill River was believed to have been constructed in 1904. Engineers working at the site have dated it between 1890 and 1900.

The bridge was widened in 1933 to include concrete sidewalks and iron rails. The rails were removed last year and discarded when restoration work was begun.

The bridge, originally 100 feet long and 58 feet wide, carries an estimated 6,450 vehicles per day. It is considered a strong contributing resource to the Tamaqua National Historic District. As such, the original stones and stone arches are being cleaned, reinforced and retained as part of a two-year overhaul.

The bridge is expected to be 116 feet long when completed.

The work is being done in coordination with Tamaqua's Historic Architectural Review Committee, Pennsylvania Historical and Museum Commission, and Department of Interior standards.

Blooming Glen Contractors Inc. of Bucks County, is the general contractor of the $2,493,465 project.

The bridge was closed to all traffic, vehicular and pedestrian, on June 3, 2013, and has remained closed since that time.

The targeted completion date is November.

Route 209 is detoured between Pine and Greenwood streets. A detour for vehicles weighing over 30 tons, or 40 tons for combinations, uses Routes 309, 54, 209, 443 and 902.