The general physiographic and geologic setting, lithostratigraphy, structural geology and regional tectonism, and depositional environments are summarized for six major coal basins in Alaska: the Susitna (Beluga and Yentna), Matanuska, Bering River, Nenana, Chignik Bay-Herendeen Bay, and Northern Alaska basins. Alaska’s Cretaceous and Tertiary subbituminous to bituminous coals are found in most physiographic regions of the state and may underlie as much as 9.0 percent of its land area. Continental Tertiary deposits are widely distributed and contain most of the subbituminous coals. Cretaceous formations contain most of the bituminous coals and usually have been influenced by marine environments during their deposition. Constraints related to paleodepositional environments affecting coal formation and character are expected to play an important role in future mine planning and pre-development site investigations in the Susitna, Nenana, Chignik Bay-Herendeen Bay, and Northern Alaska coal basins. Paleodepositional modeling will probably not greatly assist future mine planning in the Matanuska or Bering River coal basins because of complex geologic structure. Ultimately, other limiting factors such as location with respect to tidewater and potential export markets, coal quality considerations, resource base, permafrost distribution, infrastructure and port development, technological advances, and economics may determine the minability of Alaska’s vast coal resources.