The data displayed below were collected during a joint project between the following departments at Montana Tech of The University of Montana: Geophysical Engineering and the Montana Bureau of Mines and Geology. The samples represent sandstones collected and analyzed for their potential use as proppant material.

General Information
Reference Knappen, R.S., and Moulton, G.F., 1930, Geology and mineral resources of parts of Carbon, Big Horn, Yellowstone, and Stillwater Counties, Montana: U.S. Geological Survey Bulletin 822-A, 70 p.
Notes On page 37 there is information about the Eagle Sandstone, however it is not very descriptive. Much of the sandstone is interbedded with shale, clay, or coal. The Greybull Member is mentioned on page 26 but has no sandstone in its measured section. The Greybull is defined as a resistant sandstone with limonite cement with grain size less than 0.4mm. It has a high clay content.
Measured Section Details
Unit Symbol Name Township Range Section 1/4 Section Location Latitude Longitude Geomethod Datum Page Number Sub Unit Id Sandstone Description Grain Size Cementation Roundness Sorting Thickness (ft) Suitability
*t Section of the tensleep sandstone 06S 25E 7 D 45.324462821 -108.692477113 TRS-SEC NAD83 13 cream-colored to buff, argillaceous slightly calcareous, easily eroded 21 no
*t Section of the tensleep sandstone 06S 25E 7 D 45.324462821 -108.692477113 TRS-SEC NAD83 13 buff, beds 2'-6' thick, resistant to erosion and weathering very coarse 84 probably not
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 15 regular beds, cemented, veined and interlaminated with gypsum, dark to bright red coarse 55 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 gypsiferous, red-brown, thin bedded, wave ripples and cross beds not resistant to erosion 17 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 bright red, well laminated,contains a a lot of red clay, gypsum veinlets, cross bedding 50 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 grey to brown, agrillaceous, non resistant 12 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 brick red, well laminated and contains few gypsum laminae, very fine more resistant than abover 5 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 brick red fine 2 no
^c Section of the Chugwater formation 06S 24E 36 C 45.2661904274 -108.734584869 TRS-SEC NAD83 16 dark brick red, rippled fine 13 no