This database and accompanying text depict historical and modern reported
occurrences of petroleum both in wells and at the surface within the
boundaries of the Central Alaska Province. These data were compiled from
previously published and unpublished sources and were prepared for use in
the 2002 U.S. Geological Survey petroleum assessment of Central Alaska,
Yukon Flats region. Indications of petroleum are described as oil or gas
shows in wells, oil or gas seeps, or outcrops of oil shale or oil-bearing
rock and include confirmed and unconfirmed reports. The scale of the
source map limits the spatial resolution (scale) of the database to
1:2,500,000 or smaller.