Although phosphorus is a very important biogenic element, its concentration in coal is generally low. Phosphorus concentrations typically range from 0.001% to 0.1229% in raw coals of the contiguous 48 states of the U.S.A. Some Alaskan coals in the Cook Inlet region contain horizons unusually high in phosphorus. Analyses of coals at 0.3 m intervals from a deep drill core, containing 21.3 m of subbituminous C coal from the Beluga coalfield, Alaska, showed certain increments with as much as 17.03% P2O5 in the coal ash; 1.01% P on a moisture-free coal basis. Crandallite-group minerals were identified by electron microprobe analyses as phosphorus-rich minerals in these coals. Crandallite was found as 3 mu m size colloidal precipitates, and as concretions and porous aggregates as large as 100 mu m Calcium, barium, strontium and phosphorus concentrations in the coal, attributable to crandallite group minerals, can be quantified using chemical fractionation for exchangeable cations and acid extractable elements. Because high phosphorus horizons in Cook Inlet coals are attributed to periodic infusions of phosphorus from volcanic ash, as well as the proper chemical environment for the precipitation of the phosphorus minerals, it is suggested that the profiles of acid extractable phosphorus concentration may be useful to aid coal seam correlations.