Adel Mountains Volcanic Field

Last updated
Simplified geologic map of the Adel Mountain volcanic field. Adel volcanics.jpg
Simplified geologic map of the Adel Mountain volcanic field.

The Adel Mountains Volcanic Field (also known as the Adel Mountains, Adel Volcanics, and Adel Mountain Volcanics) is an ancient volcanic field of heavily eroded 75-million-year-old [1] [2] [3] igneous rocks about 40 miles long and 20 miles wide (800 square miles, or 2,071 square kilometers) [1] [4] [5] in west-central Montana about 30 miles southwest of the city of Great Falls. The area was named by geologist John Bartholomew Lyons, [6] who first described the general geology of the region in 1944. [7] The Adel Mountains Volcanic Field is a significant and abundant source of shonkinite, a very uncommon type of intrusive igneous rock found primarily in Montana, Ontario, and Timor. [1] [2] [8] [9] Because of its geologic structure, the Adel Mountains Volcanic Field has drawn the attention of geologists for more than 100 years. [10]

Contents

Description

Northwest view of Square Butte, a laccolith in the Adel Mountains Volcanic Field. Square butte.jpg
Northwest view of Square Butte, a laccolith in the Adel Mountains Volcanic Field.

The Adel Mountains Volcanic Field is a 3,280-foot (1,000 m) thick unit which lies unconformably on top of Cretaceous sedimentary rock of the Two Medicine Formation on the edge of the Great Falls Tectonic Zone. [4] [5] [11] The extrusive rock is composed of breccia and conglomerate. [5] The intrusive rock has formed numerous dikes, sills, and plugs. [5] An "enormous number of dikes...emanate radially from its center", [6] [9] [12] many of which are visually striking and vertical, and can be seen from the interstate highway and other roads in the area. [1] [5] Many of the dikes clearly fed laccoliths in the area. [9] [5] Two concentric rings of laccoliths lie in the northwest section of the field 11 miles (18 km) and 14 miles (23 km) from the center of the area. [1] [5] Square Butte, Shaw Butte (near the town of Ft. Shaw), and Cascade Butte (next to the town of Cascade) are three laccoliths belonging to the Adel field which are famous local landmarks. [1] [4] [7] More than 2,000 feet (610 m) of rock which used to exist on top of Square Butte has subsequently eroded to reveal the igneous rock which forms the laccolith. [4] Each laccolith was fed by a radial dike at its distal end where it rolled over from vertical to form the horizontal laccolith. [9] Laccoliths spread from the end of their feeder dike towards the more-elongate axis of the parent volcano, in response to load-imposed stresses of the volcano. [9]

Adel Mountain is the highest peak in the volcanic field, at 7,093 feet (2,162 m) above sea level, and an unnamed peak in the field is the second-highest at 6,845 feet (2,086 m) above sea level. [13]

Formation

The age of the Adel Mountain Volcanic Field has been re-estimated several times since 1944. Based on fossil evidence, Lyons estimated in 1944 that the formation was late Cretaceous in origin, making it about 66 million years old. [6] This estimate was reinforced in the early 1970s. [14] But separate analyses made in 1991 and 2004 re-estimated the rock as having formed in the late Cretaceous, about 81 to 71 million years ago. [5] [10] Most estimates today place the age at 75 million years. [1] [2] [3] The Adel volcanics are part of the Laramide orogeny, [15] a period of mountain building in western North America which began about 80 million years ago and ended about 35 million years ago. The age of the volcanism and thrusting overlap, with some intrusions being affected by the thrusting while others were intruded into already formed thrust horses. [16] [17]

Magma welled up from below for several million years, creating the Adel volcanics as well as the nearby Highwood Mountains and Judith Mountains. [1] [4] The crustal weakness associated with the Great Falls Tectonic Zone may have provided a route for the magma to reach the surface. [4] [5] Magma which never made it to the surface nonetheless created the many dikes, sills, plugs, and laccoliths which can be seen in the Adel volcanic field. [4] [18]

Scientists have studied the Adel Mountains Volcanic Field for a number of reasons. Several teams of scientists have analyzed the polar wander path to study continental drift. [2] [3] Others have looked at the possibility of petroleum or other hydrocarbons under the field, and concluded there is a strong possibility they exist there. [19]

Development of the area

Although not permanently inhabited by Native Americans, several tribes camped in the Adel Mountains Volcanic Field on their way to and from bison hunting rounds on the nearby plains (such as the pishkun, or buffalo jump, at nearby Ulm—the largest in the world). [4] [20] The Lewis and Clark Expedition passed up the Missouri River through the area in July 1805, becoming the first white Americans to see the formations. [4]

Development of the area did not come until the 1930s. Cattle ranchers were the area's first white settlers. [4] The primary route over the Rocky Mountains to the Pacific Ocean, the Mullan Road, skirted the volcanic field to the north, [4] although dirt stagecoach roads were built into the Missouri River Canyon in the volcanic field in the 1860s. [21] [22] The road was upgraded and turned into a toll road in 1866, and had become a major route from Helena through Great Falls to Fort Benton by the 1870s. [22] The Montana Central Railway reached the region in 1887, which led to additional white settlement. [4] A paved county road was laid down, and remained the sole access through the area for decades. [22] In the 1920s, the Montana Highway Department began planning a major highway through the area as part of their effort to build U.S. Highway 91 and provide a direct road connection between Helena and Great Falls. [4] [21] Contracts were let in 1929, the majority of construction occurred from 1931 to 1934, and the highway was completed in 1935. [4] [21] The Hardy Bridge, built over the Missouri River in 1931, was one of two major bridges built for Highway 91. [21] Interstate 15 was built largely on top of U.S. Highway 91 in 1967. [21] [22]

Climate

Climate data for Adel, Montana, 1991–2020 normals, extremes 1898–1954, 2013–present
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Record high °F (°C)64
(18)		66
(19)		70
(21)		84
(29)		90
(32)		99
(37)		106
(41)		101
(38)		96
(36)		86
(30)		75
(24)		67
(19)		106
(41)
Average high °F (°C)35.7
(2.1)		36.5
(2.5)		42.7
(5.9)		50.2
(10.1)		58.1
(14.5)		66.8
(19.3)		77.8
(25.4)		78.2
(25.7)		67.6
(19.8)		53.4
(11.9)		41.8
(5.4)		33.3
(0.7)		53.5
(11.9)
Daily mean °F (°C)25.0
(−3.9)		25.4
(−3.7)		31.8
(−0.1)		38.7
(3.7)		46.6
(8.1)		54.4
(12.4)		62.3
(16.8)		62.0
(16.7)		53.3
(11.8)		42.4
(5.8)		32.2
(0.1)		24.1
(−4.4)		41.5
(5.3)
Average low °F (°C)14.2
(−9.9)		14.2
(−9.9)		20.8
(−6.2)		27.2
(−2.7)		35.0
(1.7)		42.0
(5.6)		46.8
(8.2)		45.8
(7.7)		38.9
(3.8)		31.4
(−0.3)		22.6
(−5.2)		14.8
(−9.6)		29.5
(−1.4)
Record low °F (°C)−46
(−43)		−51
(−46)		−40
(−40)		−22
(−30)		2
(−17)		21
(−6)		25
(−4)		22
(−6)		−5
(−21)		−18
(−28)		−37
(−38)		−46
(−43)		−51
(−46)
Source 1: NOAA [23]
Source 2: National Weather Service [24]
Adel Mountains Volcanic Field about 30 miles southwest of Great Falls, Montana, USA. The Missouri River can be seen in the lower right hand corner of the image. The Hardy Bridge is in the center of the image. Adel mountains montana hardybridge.jpg
Adel Mountains Volcanic Field about 30 miles southwest of Great Falls, Montana, USA. The Missouri River can be seen in the lower right hand corner of the image. The Hardy Bridge is in the center of the image.

The final scenes of the 1974 motion picture Thunderbolt and Lightfoot was filmed on and next to Interstate 15 as it passed through the Adel volcanics. [25] A portion of the 1987 movie The Untouchables was shot at the Hardy Bridge in the Adel Mountains Volcanic Field, which doubled for the U.S.-Canada border. [26]

Motion picture star Gary Cooper was raised on the Seven Bar Nine Ranch, which was located in the Adel Mountains. [27]

The eruption that formed the Adel Mountains Volcanic Field is depicted in the third episode of the American TV series Dinosaur Planet .[ citation needed ]

Related Research Articles

<span class="mw-page-title-main">Batholith</span> Large igneous rock intrusion

A batholith is a large mass of intrusive igneous rock, larger than 100 km2 (40 sq mi) in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such as granite, quartz monzonite, or diorite.

<span class="mw-page-title-main">Coast Mountains</span> Mountain range in Canada and the United States

The Coast Mountains are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River. The mountain range's name derives from its proximity to the sea coast, and it is often referred to as the Coast Range. The range includes volcanic and non-volcanic mountains and the extensive ice fields of the Pacific and Boundary Ranges, and the northern end of the volcanic system known as the Cascade Volcanoes. The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range, the Insular Mountains, the Olympic Mountains, the Oregon Coast Range, the California Coast Ranges, the Saint Elias Mountains and the Chugach Mountains. The Coast Mountains are also part of the American Cordillera—a Spanish term for an extensive chain of mountain ranges—that consists of an almost continuous sequence of mountain ranges that form the western backbone of North America, Central America, South America and Antarctica.

<span class="mw-page-title-main">Geochronology</span> Science of determining the age of rocks, sediments and fossils

Geochronology is the science of determining the age of rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is provided by tools such as paleomagnetism and stable isotope ratios. By combining multiple geochronological indicators the precision of the recovered age can be improved.

<span class="mw-page-title-main">Laccolith</span> Mass of igneous rock formed from magma

A laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below. A laccolith forms when magma rising through the Earth's crust begins to spread out horizontally, prying apart the host rock strata. The pressure of the magma is high enough that the overlying strata are forced upward, giving the laccolith its dome-like form.

<span class="mw-page-title-main">Intrusive rock</span> Magmatic rock formed below the surface

Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form intrusions, such as batholiths, dikes, sills, laccoliths, and volcanic necks.

<span class="mw-page-title-main">Large igneous province</span> Huge regional accumulation of igneous rocks

A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive and extrusive, arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate tectonics. The formation of some of the LIPs in the past 500 million years coincide in time with mass extinctions and rapid climatic changes, which has led to numerous hypotheses about causal relationships. LIPs are fundamentally different from any other currently active volcanoes or volcanic systems.

<span class="mw-page-title-main">Solitario</span> Laccolith remnants in the state of Texas

The Solitario is a large geologic formation in Big Bend Ranch State Park in West Texas. When viewed from above, it suggests an impact crater; though it is actually the eroded remains of a laccolith. The approximate center of the Solitario is located 56.8 km (35.3 mi) east southeast of Presidio, Texas, just west of the line dividing Brewster County, Texas and Presidio County, Texas. The formation covers a circular area of approximately 135 km2 (52 sq mi). The geology of the Solitario is complex. In 1988 the state of Texas purchased the property containing the Solitario and created Big Bend Ranch State Park.

<span class="mw-page-title-main">Carrizo Mountains</span> Landform in Apache County, Arizona

The Carrizo Mountains is a small, mostly circular mountain range 15 to 20 km in diameter located on the Colorado Plateau in northeastern Arizona. The range is about 20 km (12 mi) southwest of the Four Corners. The highest summit, Pastora Peak, is 2,869 m (9,413 ft) in elevation, whereas elevations on the surrounding plateau are near 1,800 m (5,900 ft).

<span class="mw-page-title-main">Hogg Rock</span> Mountain in the Cascade Range of northern Oregon

Hogg Rock is a tuya volcano and lava dome in the Cascade Range of northern Oregon, United States, located close to Santiam Pass. Produced by magma with an intermediate andesite composition, it has steep slopes and thick glassy margins. Hogg Rock exhibits normal magnetic polarity and is probably about 80,000 years old.

In geology, a chonolith is a type of igneous rock intrusion. Igneous rock intrusions are bodies of igneous rock that are formed by the crystallization of cooled magma below the Earth’s surface. These formations are termed intrusive rocks due the magma intruding rock layers but never reaching the earth’s surface. However, sometimes portions of plutons can become exposed at the Earth’s surface and thus the minerals can be observed since they are large enough. The different plutonic formations are named based on the different shapes that the cooled crystallized magma takes. However, all plutonic formations that have irregular shapes and do not share the same characteristics as other plutonic structures are termed chonoliths. Other plutonic structures that have specific shapes include: dikes, sills, laccoliths and sheets. Another unique characteristic of chonoliths is that there is a floor or base present which is typically absent in other types of intrusions.

<span class="mw-page-title-main">Boulder Batholith</span>

The Boulder Batholith is a relatively small batholith in southwestern Montana, United States, exposed at the surface as granite and serving as the host rock for rich mineralized deposits at Butte and other locations. The batholith lies roughly between Butte and Helena, and between the Deer Lodge Valley and the Broadwater Valley. The volcanic Elkhorn Mountains are a large mass of forested lava associated with the batholith.

<span class="mw-page-title-main">Coast Range Arc</span> Volcanic arc system in the Pacific Northwest

The Coast Range Arc was a large volcanic arc system, extending from northern Washington through British Columbia and the Alaska Panhandle to southwestern Yukon. The Coast Range Arc lies along the western margin of the North American Plate in the Pacific Northwest of western North America. Although taking its name from the Coast Mountains, this term is a geologic grouping rather than a geographic one, and the Coast Range Arc extended south into the High Cascades of the Cascade Range, past the Fraser River which is the northward limit of the Cascade Range proper.

<span class="mw-page-title-main">Volcanism of Northern Canada</span> History of volcanic activity in Northern Canada

Volcanism of Northern Canada has produced hundreds of volcanic areas and extensive lava formations across Northern Canada. The region's different volcano and lava types originate from different tectonic settings and types of volcanic eruptions, ranging from passive lava eruptions to violent explosive eruptions. Northern Canada has a record of very large volumes of magmatic rock called large igneous provinces. They are represented by deep-level plumbing systems consisting of giant dike swarms, sill provinces and layered intrusions.

<span class="mw-page-title-main">Shonkinite</span> Intrusive igneous rock

Shonkinite is an intrusive igneous rock found in few places in the world. It is unique in having low silica, feldspathoid minerals, and large blocky crystals of black augite. It makes up much of the hard dark grey rock comprising certain mountains and buttes in Montana that are remnants of laccoliths and stocks, such as the Highwood mountains.

<span class="mw-page-title-main">Great Falls Tectonic Zone</span> Major intracontinental shear zone between the Hearne craton and Wyoming craton

The Great Falls Tectonic Zone is a major intracontinental shear zone between the Hearne craton and Wyoming craton basement rock of the Archean Eon which form part of the North American continent. The zone is an area about 100 miles wide extending from the southwestern Idaho-Montana border across Montana to the northwestern Montana-Saskatchewan-North Dakota border. It is named for the Great Falls of the Missouri River, a major geologic feature of the area. The central and western portions of the zone are believed to be about 1.1 to 3.3 billion years old. The central part of the zone lacks Archean rock, however, leading at least one group of scientists to speculate that it was formed very late in the Paleoproterozoic Era.

<span class="mw-page-title-main">Igneous rock</span> Rock formed through the cooling and solidification of magma or lava

Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.

<span class="mw-page-title-main">Shonkin Sag</span>

The Shonkin Sag is a prehistoric fluvioglacial landform located along the northern edge of the Highwood Mountains in the state of Montana in the United States. The Sag is a river channel formed by the Missouri River and glacial meltwater pouring from Glacial Lake Great Falls. It is one of the most famous prehistoric meltwater channels in the world.

<span class="mw-page-title-main">Tower Rock State Park</span> State park in Montana, US

Tower Rock State Park is a state park near the community of Cascade in the U.S. state of Montana in the United States. The centerpiece of the park is Tower Rock, a 424-foot (129 m)-high rock formation which marks the entrance to the Missouri River Canyon in the Adel Mountains Volcanic Field. It was well known to Native Americans, and considered a sacred place by the Piegan Blackfeet. Tower Rock received its current name when Meriwether Lewis of the Lewis and Clark Expedition visited the site in 1805. Railroad and highway development in the late 1800s and 1900s skirted Tower Rock, but the landform itself remained pristine. The 87.2 acres (0.353 km2) encompassing Tower Rock was added to the National Register of Historic Places on March 18, 2002. The 140-acre (0.57 km2) Tower Rock State Park was created around the National Historic Site in 2004.

<span class="mw-page-title-main">Kulshan caldera</span> Pleistocene caldera volcano

The Kulshan caldera is a Pleistocene volcano in the North Cascades of Washington and one of the few calderas identified in the entire Cascade Range. It is the product of the Mount Baker volcanic field, which has a history stretching back to possibly 3.722 million years ago.

<span class="mw-page-title-main">Central Montana Alkalic Province</span> Geologic area in Montana

The central Montana Alkalic Province is located in the United States in central Montana. Montana is bordered by Idaho, Wyoming, North Dakota, South Dakota, and Canada to the north. Central Montana is unique when compared to the rest of the Rocky Mountains due to its east-west trend of tectonic features, including thrust fault zones, anticlines, and domes. The area of tectonic activity experienced conditions of plastic deformation, which affected the whole region. The Montana Alkalic Province consist of Cretaceous intrusions of monzonite and syenite as well as Cambrian limestone, sandstone, and siltstone. Most of the sedimentary rocks are a result of deposition from a terrestrial fluvial environment. Deposition included more than 13,000 feet of clastics that were later uplifted. The peak of this uplifting occurred during the Devonian. Deposition, uplift, and traps of carbonate shales have made central Montana prime for small-scale oil and gas production. Other geologic formations in this area include Judith Mountains, Crazy Mountains, Highwood Mountains, and Bears Paw Mountains. These areas include various igneous formations including xenoliths, laccoliths, and veins. Each mountain exhibits similar but unique geologic features.

References

  1. 1 2 3 4 5 6 7 8 Merrill-Maker, Andrea. Montana Almanac. 2d ed. Guilford, Conn.: Globe Pequot, 2005. ISBN   0-7627-3655-0
  2. 1 2 3 4 Gunderson, Jay A. and Sheriff, Steven D. "A New Late Cretaceous Paleomagnetic Pole from the Adel Mountains, West Central Montana." Journal of Geophysical Research. 96:B1 (January 10, 1991).
  3. 1 2 3 Harlan, Stephen S.; Geissman, John W.; Snee, Lawrence W.; and Reynolds, Richard L. "Late Cretaceous Remagnetization of Proterozoic Mafic Dikes, Southern Highland Mountains, Southwestern Montana: A Paleomagnetic and 40Ar/39Ar Study." Geological Society of America Bulletin. 108:6 (June 1996).
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 "Cliffs High and Steep" - The Adel Mountain Volcanics. Montana Department of Transportation. No date. Accessed 2009-09-30.
  5. 1 2 3 4 5 6 7 8 9 Sheriff, Steven D. and Gunderson, Jay A. "Age of the Adel Mountain Volcanic Field, West-Central Montana." Isochron/West: A Bulletin of Isotopic Geochronology. December 1990.
  6. 1 2 3 Lyons, J.B. "Igneous Rocks of the Northern Big Belt Range, Montana." Geological Society of American Bulletin. 55:4 (April 1944).
  7. 1 2 Beall, Joseph J. "Pseudo-Rhythmic Layering in the Square Butte Alkali-Gabbro Laccolith." American Mineralogist. 57:7-8 (July–August 1972).
  8. ↑ Roberts, Eric M. and Hendrix, Marc S. "Taphonomy of a Petrified Forest in the Two Medicine Formation (Campanian), Northwest Montana: Implications for Palinspastic Restoration of the Boulder Batholith and Elkhorn Mountains Volcanics." Palaios. 15:5 (October 2000).
  9. 1 2 3 4 5 Hyndman, Donald W., and Alt, David. "Radial Dikes, Laccoliths and Gelatin Models." Journal of Geology. (1987).
  10. 1 2 Hearn, Jr., B. Carter. "The Homestead Kimberlite, Central Montana, USA: Mineralogy, Xenocrysts, and Upper-Mantle Xenoliths." In 8th International Kimberlite Conference: The J. Barry Hawthorn Volume. Vol. 2. T. Stachel, ed. Maryland Heights, Mo.: Gulf Professional Publishing, 2004. ISBN   0-444-51777-4
  11. ↑ Sears, James W.; Harms, Tekla A.; and Evenchick, C.A. Whence the Mountains?: Inquiries Into the Evolution of Orogenic Systems: A Volume in Honor of Raymond A. Price. Boulder, Colo.: Geological Society of America, 2007. ISBN   0-8137-2433-3
  12. ↑ Sheriff and Gunderson, "Age of the Adel Mountain Volcanic Field, West-Central Montana," Isochron/West: A Bulletin of Isotopic Geochronology, December 1990, p. 21.
  13. ↑ Daumiller, Gerry. "Montana's Tallest Peaks by Mountain Range." Natural Resource Information System. Montana State Library. Revised September 2007. Accessed 2009-09-30.
  14. ↑ Schmidt, Robert George. Geologic map of the Coburn Mountain quadrangle, Lewis and Clark and Cascade Counties, Montana. Quadrangle Map GQ-975. Washington, D.C.: U.S. Geological Survey, 1972.
  15. ↑ Burchfiel, B. Clark. "Tectonics of Noncollisional Regimes." In Continental Tectonics. Washington, D.C.: Geophysics Study Committee, Geophysics Research Board, Assembly of Mathematical and Physical Sciences, National Research Council, 1980. ISBN   0-309-02928-7
  16. ↑ Harlan, S.S., Snee, L.W., Reynolds, M. W., Mehnert, H.H., Schmidt, R.G., Sheriff, S.D. & Irving, A.J. 2005. 40Ar/39Ar and K-Ar Geochronology and Tectonic Significance of the Upper Cretaceous Adel Mountain Volcanics and Spatially Associated Tertiary Igneous Rocks, Northwestern Montana, USGS Professional Paper 1696
  17. ↑ Jolly, Arthur D. and Sheriff, Steven D. "Paleomagnetic Study of Thrust-Sheet Motion Along the Rocky Mountain Front in Montana." Geological Society of America Bulletin. June 1992.
  18. ↑ Topinka, Lyn. "America's Volcanic Past - Montana." Cascades Volcano Observatory, U.S. Geological Survey, June 11, 2003. Archived 2013-03-01 at the Wayback Machine Accessed 2009-10-01.
  19. ↑ Sears, James W.; Hansen, William B.; Ambrose, Rachele B.; Burtis, Erik W.; Hennes, Andrew M.; Hofmann, Michael H.; Laatsch, Nicholas A.; and Pallister, Beau J. "Montana's Triangle Zone." Rocky Mountain - 54th Annual Meeting of the Geological Society of America. May 7–9, 2002.
  20. ↑ The Ulm pishkun is the centerpiece of the First Peoples Buffalo Jump State Park in Montana, and the largest buffalo jump in the world. See: Conklin, Dave. Montana History Weekends: 52 Adventures in History. Guilford, Conn.: Globe Pequot, 2002. ISBN   0-7627-1161-2
  21. 1 2 3 4 5 Axline, Jon. Conveniences Sorely Needed: Montana's Historic Highway Bridges, 1860-1956. Helena, Mont.: Montana Historical Society, 2005. ISBN   0-9721522-6-1
  22. 1 2 3 4 Axline, Jon and Bradshaw, Glenda Clay. Montana's Historical Highway Markers. Rev. ed. Helena, Mont.: Montana Historical Society, 2008. ISBN   0-9759196-4-4
  23. ↑ "U.S. Climate Normals Quick Access – Station: Adel, MT". National Oceanic and Atmospheric Administration. Retrieved December 5, 2023.
  24. ↑ "NOAA Online Weather Data – NWS Great Falls". National Weather Service. Retrieved December 5, 2023.
  25. ↑ Jim, Shirley Rose Higgins. "A Safe-Cracking Yarn Filmed in Montana." Chicago Tribune. May 26, 1974.
  26. ↑ Barth, Jack. Roadside Hollywood: The Movie Lover's State-By-State Guide to Film Locations, Celebrity Hangouts, Celluloid Tourist Attractions, and More. Chicago: Contemporary Books, 1991. ISBN   0-8092-4326-1
  27. ↑ Parish, James Robert; Stanke, Don E.; and Pitts, Michael R. The All-Americans. New York: Arlington House, 1977. ISBN   0-87000-363-1; Eastman, John. Who Lived Where: A Biographical Guide to Homes and Museums. New York: Facts on File Publications, 1985. ISBN   0-87196-562-3

"Adel Mountain". Geographic Names Information System. United States Geological Survey. Retrieved 2013-12-31.

47°04′34″N111°42′24″W / 47.07606°N 111.70665°W / 47.07606; -111.70665

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.