To supplement the work reported by the senior author in Bulletin 290 of the Utah Agricultural Experiment Station, the writers have visited the phosphate outcrops in Weber, Morgan and Salt Lake Counties, as well as those in the Park City District of Summit County and others west of Midway in Wasatch County. These areas were found to contain considerable phosphatic shale of 25 to 35 percent grade, but no rock of 40 percent grade, the minimum quality included in the estimates in Bulletin 290. However, the data recorded for the sections visited are valuable in showing the leanness of these areas, which because of their proximity to the industrial centers of the state, have often been suggested for early development. It seems in this case almost as important to tabulate the value of a resource of debated quantity and quality as to discover a new one.
On the basis of these results the tables from Bulletin 290 setting forth Utah's reserve of phosphate by areas, by counties and by quality of rock are revised and restated.
Williams, J. Stewart and Hanson, Alvin M., "Bulletin No. 304 - Phosphate Reserves of Utah" (1942). UAES Bulletins. Paper 266.