- Bowers, William E., 1991, Geologic map and coal deposits of the Horse Mountain Quadrangle, Kane County, Utah: Coal Map 137, 1 map :col. ;57 x 46 cm., on sheet 91 x 83 cm., folded in envelope 30 x 24 cm.,
- Bowers, William E., 1991, Geologic map of the Fourmile Bench Quadrangle, Kane County, Utah: Coal Map 140, 1 map :col. ;58 x 46 cm., on sheet 84 x 81 cm., folded in envelope 30 x 24 cm.,
- Gualtieri, James Louis, 1991, Map and cross sections of coal zones in the Upper Cretaceous Neslen Formation, north-central part of the Westwater 30‘ x 60‘ Quadrangle, Grand and Uintah counties, Utah: Coal Map 133, 2 maps on 1 sheet :col. ;57 x 75 cm. and 28 x 35 cm., sheet 104 x 109 cm., folded in envelope 30 x 24 cm. +2 sheets (101 x 117 cm. and 104 x 122 cm.),
- Gualtieri, James Louis, 1991, Map and cross sections of coal zones in the Upper Cretaceous Neslen and Mount Garfield formations, northeastern part of the Westwater 30‘ x 60‘ Quadrangle and adjacent area, Garfield County, Colorado, and Grand and Uintah counties, Utah: Coal Map 134, 1 map :col. ;69 x 90 cm., on sheet 104 x 137 cm., folded in envelope 30 x 24 cm. +2 sheets (93 x 137 cm. and 96 x 129 cm.),
- Roberts, Laura N. R.; Uptegrove, Jane, 1991, Coal geology and preliminary coal zone correlations in the Fruitland Formation, western part of the southern Ute Indian Reservation, La Plata County, Colorado: Coal Map 138, 1 map :col. ;58 x 46 cm., on sheet 91 x 132 cm., folded in envelope 30 x 24 cm.,
- Roberts, Stephen B., 1991, Subsurface cross section showing coal beds in the Sagavanirktok Formation, vicinity of Prudhoe Bay, east-central North Slope, Alaska: Coal Map 139-A, 1 section ;sheet 89 xz 127 cm., folded in envelope 30 x 24 cm.,
- Roberts, Stephen B.; Stricker, Gary D.; Affolter, Ronald H., 1991, Stratigraphy and chemical analyses of coal beds in the Upper Cretaceous and Tertiary Sagavanirktok Formation, east-central North Slope, Alaska: Coal Map 139-B, 13 sections on 1 sheet ;sheet 104 xz 147 cm., folded in envelope 30 x 24 cm.,
