Telegraph Creek formation (MTKtc;0)

State	Montana
Name	Telegraph Creek formation
Geologic age	Phanerozoic \| Mesozoic \| Cretaceous-Late
Original map label	Ktc
Primary rock type	mudstone
Secondary rock type	sandstone
Other rock types
Lithologic constituents	Major Sedimentary > Clastic > Sandstone (Bed) Sedimentary > Clastic > Mudstone (Bed)
Map references	Ross, P.R., Andrews, D.A., and Witkind, I.J., 1955, Geologic map of Montana: U.S. Geological Survey, 2 sheets, scale 1:500,000.
Unit references	Chadwick, R.A., 1972, Volcanism in Montana: Northwest Geology, v. 1, p. 1-20. Lopez, D.A., 2001, Geologic map of the Sweet Grass Hills 30' x 60' quadrangle, north-central Montana: Montana Bureau of Mines and Geology Open File Report 443, 4 p., scale 1:100,000. Viele, G.W. and Harris, F.G., III, 1965, Montana Group stratigraphy, Lewis and Clark County, Montana: American Association of Petroleum Geologists Bulletin, v. 49, no. 4, p. 379-417. Schmidt, R.G., 1972, Geologic map of the Coburn Mountain quadrangle, Lewis and Clark and Cascade Counties, Montana: U.S. Geological Survey Geologic Quadrangle Map GQ-975, 1 sheet, scale 1:24,000. [http://pubs.er.usgs.gov/publication/gq975] Obradovich, J.D. and Cobban, W.A., 1975, A time-scale for the Late Cretaceous of the Western Interior of North America, in Caldwell, W.G., ed., The Cretaceous System in the Western Interior of North America: Geological Association of Canada S Skipp, Betty and McGrew, L.W., 1977, The Maudlow and Sedan Formations of the Upper Cretaceous Livingston Group at the west edge of the Crazy Mountains basin, Montana, in Contributions to stratigraphy: U.S. Geological Survey Bulletin 1422-B, p. [http://pubs.er.usgs.gov/publication/b1422B] Richards, P.W. and Rogers, C.P., Jr., 1951, Geology of the Hardin area, Big Horn and Yellowstone Counties, Montana: U.S. Geological Survey Oil and Gas Investigations Map OM-111, 2 sheets, scale 1:63,360 (Reprinted 1975). [http://pubs.er.usgs.gov/publication/om111] Lopez, D.A., 2000, Geologic map of the Billings 30' x 60' quadrangle, Montana: Montana Bureau of Mines and Geology Geologic Map 59, scale 1:100,000. Merewether, E.A., 1996, Stratigraphy and tectonic implications of Upper Cretaceous rocks in the Powder River basin, northeastern Wyoming and southeastern Montana, in Evolution of sedimentary basins--Powder River basin: U.S. Geological Survey Bul [http://pubs.er.usgs.gov/publication/b1917T]
Geographic coverage	Big Horn - Carbon - Chouteau - Fergus - Glacier - Judith Basin - Liberty - Park - Pondera - Stillwater - Teton - Toole - Yellowstone