ROUSEVILLE, Pa. – The world’s oldest continually producing oil well has made it to its 150th birthday in northwestern Pennsylvania.

Dozens of people gathered Tuesday in Rouseville, near Route 8, to mark the occasion at McClintock Well No. 1. The well, about 70 miles north of Pittsburgh, was drilled on Aug. 16, 1861, about two years after Edwin Drake drilled the world’s first oil well in Titusville, about 10 miles farther north.

The 200-foot-deep well initially produced about 175 barrels a day. Production eventually fell to about 50 barrels daily, and the well changed hands before it came to be owned by Quaker State, now part of Sopus Products Inc.

Today, the well produces about 40 barrels per year. The National Park Service declared the well an American Treasure in 1999.