Lovell Mill

Bighorn County, Wyo.

• Old Hickory Clay Company (2005, 2006, 2007, 2008, 2009 & 2010) – 508,428 hours

Hickory Clay Mill

Graves County, Ky.

• Imerys (2007 & 2010) - 492,974 hours

Three Forks Mill

Gallatin County, Mont.

• KaMin LLC (2010) – 428,878 hours

Sandersville Plant

Washington County, Ga.

• U.S. Silica (2003 & 2004) - 389,983 hours

Kosse Plant

Limestone County, Texas

• Carmeuse Lime & Stone Inc. (2009 & 2010) – 339,834 hours

Middletown Quarry

Frederick County, Va.

• Imerys (2009 & 2010) – 326,025 hours

Deepstep Land and Mines

Washington County, Ga.

• Imerys (2005, 2007 & 2008) – 293,947 hours

Sandersville Calcine Plant

Washington County, Ga.

• A.F. Gelhar Co., Inc. (2009 & 2010) – 277,148 hours