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You searched for: geology Remove constraint geology Publisher State of Pennsylvania Remove constraint Publisher: State of Pennsylvania Subject Biota Remove constraint Subject: Biota
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Ecoregions United States (Omernik) penn-state

2003. U S Environmental Protection Agency. This map layer shows Omernik's Level III ecoregions, derived from a 1:7,500,000 map created by J.M. Omernik in 1987 and from refinements of Omernik...