Compiled under the direction of the State Geologist: J.P. Lesley.
Geologists and assistant geologists: Isaac A. Harvey, Alfred G. Prosser and Edward B. Harden.
Octavo atlas contains: geol. maps of Cambria and Somerset Counties (2 sheets) ; columnar sections in Cambria County (2 sheets) ; cross section through crest of the Allegheny Mountain (1 sheet).
With: Revision and correction of the semi-bituminous coal section at Wellersburg in Somerset County, Pa. : a continuation of Report HHH / J.P. Lesley. (p. 349-360) Reprinted from the Annual Report of the Geological Survey for 1885.
With: Notes on Cambria County / John Fulton. (p. 361-396).
With: Notes on the new mines of Somerset County / A.G. Prosser. (p. 397-404).
Map caption titles: Geological Survey of Pennsylvania.