bluuebunny/crossref_metadata_2025 huggingface dataset:
Depositional surfaces in the Eagle Sandstone at Billings, Montana
Authors: Hansen William B. , Kendrick Kevin R.
Published: November 2007

The lower sandstone unit of the Upper Cretaceus Eagle Sandstone is extensively exposed in a 300-ft (100-m) high cliff which is dangerously sheer in places and rises above the north edge of Billings, Montana (Fig. 1). An excellent view of the cliffs from a distance can be seen from Rocky Mountain College. The safest and most accessible place to examine the outcrop is in Swords Park, a city park open to the public and accessible by two-wheel drive vehicles.
The Hebgen Lake Earthquake Area, Montana and Wyoming
Authors: Witkind Irving J. , Stickney Michael C.
Published: November 2007

The Hebgen Lake Earthquake Area, in southwestern Montana, extends westward from the east edge of Hebgen Lake through the Madison River Canyon, a narrow, deep gorge cut through the Madison Range, to Missouri Flats, west of the range. Hebgen Lake, about 8 mi (13 km) north of West Yellowstone, Montana, lies at the base of the east flank of the Madison Range directly west of the northwest corner of Yellowstone National Park, Wyoming. The lake is used as a storage reservoir impounded behind Hebgen Dam, an earth-filled structure built by Montana Power Company in 1914.

The earthquake area is easily reached from almost any direction by major all-weather surfaced highways (inset map, Fig. 1). The area is accessible from the east through Yellowstone Park’s West Entrance, which leads directly into West Yellowstone; from the south by multi-lane U.S. 20, which also passes through West Yellowstone; from the north via U.S. 191, which threads then arrow, deeply forested and scenic Gallatin Canyon; and from the west via U.S. 287, which passes through Ennis, a ranching center that still retains the flavor of the old west. The West Yellowstone airport also gives access to the area.

The Hebgen Lake area is a favorite tourist and reort area. Lodging is available in West Yellowstone and at several motels along the north shore of Hebgen Lake. Excellent campsites, well maintained by the U.S. Forest Service, are along U.S. 191 north of West Yellowstone, and in Madison River Canyon (Montana 287) west of Hebgen Dam. Most services are available throughout the year in West Yellowstone, although many hotels and some restarants close for the winter soon after Labour Day.
Upper Cretaceus coastal plain sediments at Dinosaur Provincial Park, southeast Alberta
Authors: Koster Emlyn H. , Currie Philip J.
Published: November 2007

Dinosaur Provincial Park, a UNESCO World Heritage Site 112 mi (180 km) east of Calgary, Alberta, occupies part of a large tract of badlands along the Red Deer River valley in the semi-arid southeast Alberta plains (Fig. 1). Access is from the Trans-Canada Highway at Brooks (where all major services are available), northeastward 30 mi (48 km) on Alberta Highways 873, 554, and 551. The Park is fully operative from May 15 to September 15; camping facilities are limited with a small retail food outlet. Access to outcrop requires dry weather, and precautions should be taken for extreme heat, rough terrain and occasional rattlesnakes. Provincial regulations prohibit the extraction of any fossil material.

In terms of visitor access, the badlands are divided into two areas (Fig. 1). First, Dinosaur Park encloses 23 mi2 (60 km2) of crown land flanking the river for 16 mi(25 km) downstream from the Steveville bridge on Alberta Highway 876. It is subdivided into a small public area surrounding the campground and a Natural Preserve into which bus tours and hikes are regularly conducted by Park officials. Inquiries about further access to the Natural Preserve should be directed to Park officials (403/378-4587). Plans are underway to relocate the Park headquarters approximately 1.2 mi (2 km) upstream and to expand visitor services. Secondly, the extensive privately owned badlands that surround the Park continue eastward to the bridge crossing on Alberta Highway 884, north of Jenner. With arugged vehicle and local landowner permission, the prairie edge is reached by a network of dirt tracks
Surface faulting associated with the 1983 Borah Peak earthquake at Doublespring Pass road, east-central Idaho
Authors: Crone Anthony J.
Published: November 2007

The Doublespring Pass road site is an excellent location at which to examine the surface faulting and ground breakage that accompanied the 1983 Borah Peak earthquake. The site can be reached by traveling 23 mi (37 km) northwest from Mackay, Idaho, or 30 mi (48 km) southeast from Challis, Idaho (Fig. 1), on U.S. 93 to the Doublespring Pass road turnoff. The Doublespring Pass road heads northeast from the highway. The intersectionof the Doublespring Pass road with the highway is identified by a sign indicating the direction to the towns of May and Patterson. The turnoff is also identified at the intersection by a historical marker commemorating William E. Borah, after whom Borah Peak was named. The Doublespring Pass road crosses thefault scarps 2.5 mi (4 km) northeast of the intersection of U.S. 93 (Fig. 2).

Doublespring Pass road is a wide, well-maintained gravel road that can be safely traveled by passenger car and bus to the site (although the road is impassable at times in the winter and early spring when snow covers the area). The site lies within Challis National Forest and is open to the public.
Late Cenozoic stratigraphy and geomorphology, Fort Niobrara, Nebraska
Authors: Voorhies M. R.
Published: November 2007

The central Niobrara River valley in northern Nebraska(Fig. 1) has played an important role in the conceptual development of late Tertiary stratigraphy and vertebrate paleontology in the Great Plains. Much of our current understanding of the evolution of such mammals as horses, camels, and proboscideans is based on fossils collected from the Valentine and Ash Hollow Formations exposed in the deep (by Nebraska standards!)canyons of the Niobrara River and its tributaries in Brown, Cherry, and Keya Paha Counties. The Valentine-Ash Hollow sequence in this area represents the northernmost expression of a complex of alluvial deposits collectively known as the Ogallala (variously termed agroup or formation) which blankets much of the Great New Mexico.

The only paved road to traverse reasonably good exposures of the classic Ogallala sequence in the Niobrara valley is Nebraska 12 about 3 mi (4.8 km) northeast of Valentine. Two adjacent road cuts at the northwestern margin of Fort Niobrara National Wildlife Refuge (see. 22, T.34N., R.27W., Cornell Dam Quadrangle, Fig. 2) expose nearly the entire thickness of the Valentine Formation and the Cap Rock Member of the Ash Hollow Formation. Examination of the road cuts, combined with a tour of the Refuge, will provide the visiting geologist with an overview of the later Tertiary mantle of the Great Plains near the boundary between the latter physiographic province and the Central Lowlands Province to the east. Geomorphological relation ships are also exceptionally clear along this segment of the Niobrara River; the very late
Late Cenozoic geology along the summit to museum hiking trail, Scotts Bluff National Monument, western Nebrasak
Authors: Swinehart James B. , Loope David B.
Published: November 2007

Scotts Bluff National Monument is best reached by starting from the junction of Nebraska 71 and 92 in downtown Gering, Nebraska, and proceeding westward on Nebraska 92 for 2.4 mi(3.4 km) to the visitor center (Fig.1). The monument is open from 8 A.M. to 8 p. M. Memorial Day to Labor Day, 8 A.M. to 6 p. M. Labor Day to October 1, and 8 A.M. to 5 p. M. October 1 to Memorial Day. Educational groups are not charged the nominal usage fee for admittance to the summit road and parking(Fig.2). Please stay on the trails and note that collecting rocks or other items is prohibited without a permit from the National Park service.
Lover’s Leap, type section Hannibal Shale, Missouri
Authors: Thompson Thomas L.
Published: November 2007

This is a major Mississippi River bluff exposure above a road next to the railroad yard on the southeast edge of Hannibal, Marion County, Missouri, just west of center of SE¼ Sec. 28, T.57N., R.4W., Hannibal East 7½-minute Quadrangle (Fig. 1).
Geology of the Circumferential Highway System at Kansas City, Missouri
Authors: Gentile Richard J.
Published: November 2007

This section is a roadcut at the 1-470 exit at Raytown Road(SW¼NW¼Sec.33, T.48N., R.32W., Jackson County, Missouri, Lees Summit 7½-minute Quadrangle (Figs. 1 and 2). Park along Raytown Road north of the bridge over 1–470 and walk east along the access road and onto the grassy strip of right-of-way about 200 ft (60 m) wide on the north side (westbound lane) of 1–470. The section, with faults, is exposed about 1000 ft (300 m) east of Raytown Road.
Hahatonka karst landform complex, Camden County, Missouri
Authors: Hebrank Arthur W.
Published: November 2007

Ha Ha Tonka State Park, Sec. 2 and W½SW¼Sec. 1, T.37N., R. 17 W., Camden County, Missouri;Hahatonka 7½-minute Quadrangle. Entrance to Ha Ha Tonka State Park is on State Road D (Fig. 1), about 2.3 mi (3.7 km) southeast of its junction with Missouri 54, west of Camdenton, Missouri. Well-designed and well-maintained trails within the park provide access to all major features of interest (Fig. 1). The site is on public land. Note: State park rules prohibit defacing or collecting rocks.
Potosi-Highway 8 Cambrian exposure, southeastern Missouri
Authors: Thompson Thomas L. , Palmer James
Published: November 2007

This composite section consists of a sequence of roadcuts on Missouri 8, between the town of Flat River and the bridge over Big River, St. Francois County, Missouri (Fig. 1). It comprises strata from upper Bonneterre Formation to basal Derby-Doerun Dolomite; the entire Davis Formation is represented. This exposure is within 3 mi (4.8 km) of the type section of the Davis Formation (SW¼Sec.7,T.36N.,R.5 E., to NE¼Sec.13,T.36N., R.4E.), where approximately 170 ft (52 m) of Davis strata have been described (Buckley, 1908)
Silver Mine district
Authors: Kisvarsanyi Eva B. , Hebrank Arthur W.
Published: November 2007

NW¼SW¼SE¼Sec.12, T.33N., R.5E., Silver Mine Dam on St.Francis River, Madison County, Missouri; Rhodes Mountain 7½-minute quadrangle.From the junction of Missouri 72 and Missouri D at Oak Grove, follow Missouri D south and southwest for 3.3 mi (5.2 km) to the parking lot adjacent to the picnic area on the east side of the road, about 200 ft (60 m) south of the bridge across the St.Francis River (Fig. 1).Cross the road and walk uphill west then north onthe prominently marked foot trail leading to the historic Einstein Silver Mine and the Silver Mine Dam.The trail roughly parallels the river for about 2,000 ft (600 m) to the mine.About 1, 500 ft (450 m) Missouri D, the trail joins an old wagon road carved into bedrock; bear right and follow the old wagon road downhill to the mine and dam.To return to the parking lotretrace the trail to the mine or, if conditions permit, cross the St.Francis River at the dam and follow the trail along the eastern bluffs of the river.The site is on public land.
Taum Sauk Power Plant section
Authors: Kisvarsanyi Eva B. , Hebrank Arthur W.
Published: November 2007

NE¼SE¼SW¼Sec.21, T.33N., R.2E., Taum Sauk Power Plant, Reynolds County, Missouri; Johnson Shut-ins 7½-minute Quadrangle. The site is 10.8 mi (17.3 km) west ofthe village of Hogan, in Iron County, and can be reached by Missouri AA or, from Lesterville, in Reynolds County, by Missouri U (Fig. 1).The site is owned by the Union Electric Company and is open daily to visitors.A small museum is in the nearbyVisitor Center.
Precambrian/Paleozoic unconformity at Chippewa Falls, Wisconsin
Authors: Ostrom M. E.
Published: November 2007

Stream cut in east bank of Duncan Creek just northof first bridge south of Glen Lock Dam in Irvine Parknear north city limits of Chippewa Falls (Fig. 1) in the NW½, SW½, NE½, Sec.31, T.29N., R.8W., Chippewa County (Chippewa Falls 7¼-minute Quadrangle, 1972). Exposure can be reached by foot path from northeast side of bridge northward for about 300 ft (90 m).
Late Cambrian Eau Claire Formation at Strum, Wisconsin
Authors: Ostrom M. E.
Published: November 2007

Abandoned quarry at east side of County Trunk Highway D 0.2 mi (0.3 km) north of its junction with U.S.10 at the north edge of the village of Strum in the NW¼, NE¼, SE¼, Sec.18, T.24N., R.8W., Trempealeau County, Wisconsin, Strum 7½-minute Quadrangle (Fig. 1).
Archean gneiss at Lake Arbutus Dam, Jackson County, Wisconsin
Authors: Maass R. S. , Brown B. A.
Published: November 2007

SE¼, Sec.3, T.22N., R.3W., Hatfield 7½-minute Topographic Quadrangle.Outcrop along the Black River below the eastern half of Arbutus Dam (Fig. 1). Approach is on a 0.2-mi-long (0.3 km) gravel road that intersects Clay School Road 0.1 mi (0.2 km) west of the Green Bay and Western Railroad tracks.Additional outcrop occurs for 0.6 mi (1 km) downstream from dam.
Proterozoic quartzite at Hamilton Mound, central Wisconsin
Authors: Brown B. A. , Greenberg J. K.
Published: November 2007

The quarry at Hamilton Mound is in the NE¼, Sec.36, T.-20N., R.6E., Coloma NW 7½-minute Quadrangle. It can be reached by turning east from Wisconsin 13 on Archer Drive, just north of Dorro Couche Lake, and proceeding about 4 mi (6 km) to a turnoff leading south into the quarry in the middle of Hamilton Mound.The turnoff from Wisconsin 13 is about 15 mi (24 km) south of Wisconsin Rapids (Fig.1).
Middle Ordovician rocks at Potosi Hill, Wisconsin
Authors: Ostrom M. E.
Published: November 2007

Roadcut at east side of U.S. 61 and Wisconsin 35 about 1 mi (1.6 km) northwest of bridge over Platte River and 4 mi (6.4 km) northwest of Dickeyville in the SE¼, NW¼, Sec.7, T.2N., R.2W., Grant County, Wisconsin in the Potosi 7½-minute Quadrangle (Fig. 1).
Middle Ordovician Platteville Formation, Hoadley Hill, Wisconsin
Authors: Ostrom M. E.
Published: November 2007

Exposure in roadcut at north side of U.S. 151 about 6.5 mi (10.8 km) southwest of Platteville in the W½, NE¼, Sec.12, and the W½, SE¼, Sec.1, T.2N., R.2W., Grant County, Wisconsin on the Dickeyville 7½-minute Quadrangle (Fig. 1).
The Silurian reef at Thornton, Illinois
Authors: Mikulic Donald G.
Published: November 2007

The Thornton Reef is exposed in quarries owned by the Material Service Corporation and in roadcuts along 1-80 and 1-294, about 4.8mi(8km) west of the Illinois-Indiana boundary (Figs. 1 and 2), in the W¼,Sec.27,N¼Sec.33,T.36N.,R.13E,Harvey and Calumet City 7¼-minute Quadrangles, Thornton, Cook County, Illinois.
Wedron Section, Wedron, Illinois
Authors: Johnson W. Hilton , Hansel Ardith K. , Follmer Leon R.
Published: November 2007

The Wedron Section is located in the Wedron Silica Quarry, Sees. 8, 9, 10, and 16, T. 34 N., R. 4 E., La Salle County, Illinois, 4 mi (6.4 km) north of 1-80 andjust west of the Fox River (Fig.1). From 1-80, exit north on Illinois 71 and continue northeast for 3 mi (4.8 km); turn west on Wedron Road and proceed 3 mi (4.8 km) to the entrance to the Wedron Silica Company in Wedron. To enter the quarry, permission must be obtained from the Wedron Silica Company (phone number 815– 433–2449). Exposures in the quarry are accessible by vehicle; high axle clearance is usually essential.
Starved Rock, Illinois
Authors: Kolata Dennis R.
Published: November 2007

Starved Rock is on the south bank of the Illinois River, 1.5mi (2.4 km) southeast of Utica in La Salle County, Illinois (Sec.22, T.33N., R.2E.; Starved Rock 7½-minute Quadrangle). It ispart of Starved Rock State Park, which consists of 2, 630 acres(1, 052 ha) of wooded area along a7mi(11.2 km) stretch of theriver midway between La Salle-Peru and Ottawa (Fig. 1).

The main entrance to the park is accessible from 1-80 or U.S. 51. Leave 1-80 at exit81 and proceed south on Illinois 178through Utica and across the Illinois River. Turn left at the parkentrance 0.25 mi (0.4 km) south of the river. From U.S. 51 turnnortheast on Illinois 71 and proceed north through Oglesby. Turneast at Jonesville and continue along Illinois 71 to Illinois 178and turn left. The park entrance is on the right, 0.75 mi (1.2 km)north of the Illinois 71-178 intersection. Groups of 25 or morepeople must receive permission from the Site Superintendent, Starved Rock State Park, Box 116, Utica, Illinois 61373 (phone 815-667-4726). Starved Rock can be viewed and photographed on the north side of the Illinois River at the Starved Rock Lockand Dam.
Duer Ranch, Merrill County, Nebraska
Authors: Swinehart James B. , Diffendal R. F.
Published: November 2007

The Duer Ranch locality is situated on either side of U.S. 26 in southeastern Merrill County, Nebraska, halfway between the villages of Lisco and Broadwater and about 54 mi (90 km)southeast of Scottsbluff, Nebraska. The Rush Creek Land and Livestock Company currentlyowns all of sections 28, 29, 33, 34, and 35 of T. 19 N., R.47 W., as well as parts of sections 2, 3, 4, 10, and 11 of T. 18N., R.47W. (Broadwater and Tar Valley SW, 7½-minute Quadrangles; Fig. 1). The owners have allowed geologists to study the exposures on ranch property providedthat visitors stop at the ranch headquarters (Fig. 1) and obtain permission from the ranch foreman. Vehicles shouldbe parked inside the gate on thenorth side of U.S. 26 in the SW¼ Sec. 3, T.18N., R47.W. (Fig. 1), and all study ofthe site should be done on foot.Be certain to closeany gates that you open, anddo not smoke on the property. Rattlesnakes are found on the ranch. If you have asmall group and wish to examine the exposures in the southeast corner of the locality, two vehicles can park safely along the north side of the road cut on U.S. 26 in the NE¼ NW¼ sec. 10, T.18N., R.47W.
Farm Creek, central Illinois
Authors: Follmer Leon R. , McKay E.Donald
Published: November 2007

The Farm Creek Section is located in central Illinois, nearthe late Wisconsinan glacial margin east of Peoria, Illinois(Fig. 1). The section is a cut bank along Farm Creek in the Farmdale Recreation Area, a public park adjacent to East Peoria(Fig. 2)It is about 5 mi (8.5 km) east of Peoria via I-74 and Illinois 8 to Robein or to Farmdale via Farmdale Road Fig. 3)Either route provides access to the west entrance of the park. Turn south on Summit Drive 1.5 mi (2.4 km) east of Robein. This roadturns into Bitter sweet Road and provides a scenic view of the parkin the valley on the way to the west entrance. Farmdale Road goesup Farm Creek Valley through Farmdale, a former station on the Toledo, Peoria, and Western Railroad. East of Farmdale, turn north on Summit Road to the west entrance of Farmdale Park.

The east entrance to the park is off School Road about 0.5 mi(0.8 km) east of Summit Drive. During good weather one can drive on a gravel road from one entrance to the other but mustcross three concrete-bottom fords. The main geologic section, on the south side of the creek near the middle ford can be seen from the road.

Farm Creek is subject to flash floods that sometimes bury the fords with gravel or cause structural damage. The bottomland road is usually closed for repairs following floods; at such time shiking from the east entrance along the railroad track to
Geologic features near Grand Tower, Illinois
Authors: Fraunfelter George H.
Published: November 2007

The Devil’s Backbone, the Devil’s Bake Oven, and Fountain Bluff are located in extreme southwestern Illinois in Jackson County, adjacent to the Mississippi River (Fig. 1). All three sites are shown along the southeastern edge of the Altenburg 7½-minute Quadrangle; the remainder of Fountain Bluff is shown on the Gorham 7½-minute Quadrangle. Locality 1, the Devil’s Backbone, and Locality 2, the Devil’s Bake Oven, are situated in Grant Tower City Park on the northwest side of town; Locality 3, Fountain Bluff, is about 1 mi (1.6 km) north of town. All sites are readily accessible via car and short walks.

Locality 1. The Devil’s Backbone: abandonedquarry on southeast end of ridge, SE¼SW¼SW¼Sec.24, T.10S., R.4W., 3rdp. M. (Fig. 2). Locality 2. TheDevil’s Bake Oven: center ofS½4NE¼Sec.23, T.10S., R.4W., 3rdp. M. Locality 3. Draw situatedalong the southwestern side of Fountain Bluff, SE¼NW¼-Sec.13, T.10S., R.4W., 3rdp. M. Access to the latter site may be gained by asking the owner, who lives in the white frame house just across theroad to the south of the draw, and less than 0.25 mi (0.4 km) northwest of the T-road intersection near the center of the NE¼SW¼Sec.13.
Fluvial-deltaic deposits (Caseyville and Abbott Formations) of Early Pennsylvanian age exposed along the Pounds Escarpment, southern Illinois
Authors: Jacobson Russell J.
Published: November 2007

I-24 passes through the lower Pennsylvanian rocks of the Pounds Escarpment, roughly 10 to 20 mi ( 15 to30 km) south of Marion, Illinois (Fig. 1). This escarpment is a cuesta formed of resistant basal Pennsylvanian sandstones. Roadcuts along the interstate have made accessible nearly all of the Caseyville Formation and the basal portion of the Abbot Formation. The roadcuts are approximately 20.5 mi (33 km) south of the interchange of Illinois 13 with I-57 at Marion, Illinois (Fig. 1), and 2.7 miles(4.3 km) north of the Vienna interchange of U.S. 45 with I-24.

Figure 2 shows the exact location of the I-24 roadcuts on aportion of the Vienna 7½-minute Quadrangle.The upper roadcut is in the E½NE¼Sec.8, T.12S., R.3E., Johnson County, Illinois.The lower cut is found in the E½NE¼Sec. 17, and the NW¼ Sec.16, T.12S., R.3E., Johnson County, Illinois.

The Pennsylvanian rocks are well exposed in lower and upper sets of cuts on both sides of the interstate. The shoulders are wide and paved, and provide room for a group of vehicles to pull completely off the road. However, it is still advisable for any large group planning a formal field trip to first check with the state police.

Separate cuts have been made for the northbound and southbound lanes on I-24; thus, four walls of rock are present and separate stops can be made (Fig. 2).
Anomalous Paleozoic outliers near Limestone Mountain, Michigan
Authors: Milstein Randall L.
Published: November 2007

Limestone Mountain, Sec.13, 14, 23, 24, T.51W., R.35W., Houghton County, Michigan; Pelkie, Michigan, 7½-minuteQuadrangle. Limestone Mountain is located 1 mi (1.6 km) northeastof Hazel, Michigan (Fig. 1). Access to Limestone Mountainis by private road or foot trail. The trail head is located on thewest side of Limestone Mountain Road, 800 ft (244 m) south ofthis road’s intersection with Papin Road (Fig. 1). Limestone Mountain is located on privately owned wilderness land, and permission should be obtained prior to entry.
Porcupine Mountains Wilderness State Park, Michigan
Authors: Reed Robert C.
Published: November 2007

The Porcupine Mountains State Park is located in the northwestern part of Michigan’s northern peninsula. The parkoccupies all of T.50N., R.45W.; T.5lN., R.43W.; T.5lN., R.44W.;and portions of T.49N., R.45W.; T.50N., R.43W.; T.50N., R.44W.; and T.51N., R.42W. in Ontonagon and Geogebic Counties (Fig. 1). The area of the park is covered by the Carp River and TiebelCreek 7½ by 15-minute Quadrangles and the Aldrige Creek, Bergland NE, Government Peak, and White Pine 7½-minute Quadrangles. The principal entrance to the park s via Michigan 107 west of Silver City. Silver City ilocated 13 mi (21 km) westOntonagon on Michigan 64 and 18 mi (29 km) north of Berglandon Michigan 64. Alternate access is provided by CountyRoad 51916 mi (26 km) north of Wakefield. County Road 519intersects the park’s South Boundary Road which extends northand east to Michigan 107. A visitors/ center is located south of theintersection of Michigan 107 and the South Boundary Road. Forpark visitors, it is extremely advisable not to feed the bears.Further information about Porcupine Mountains State Park maybe obtained from Park Manager, Porcupine Mountains StatePark, 599 M-107, Ontonagon, Michigan 49953.
Huron River
Authors: Kalliokoski J. , Lynott Jeffrey S.
Published: November 2007

Big Eric’s Crossing (Fig. 1, Site 1) is a county bridge acrossthe Huron River (NW¼NW¼Sec.35, T.52N., R.30W.), Skanee, Michigan 15-minute Quadrangle, about 12 mi (19 km) northeastof L/Anse, Michigan, along the road that continues north fromMain Street. The second locality (Site 2), a small, southeastfacinggranite hill, (SE¼:SE¼Sec.26) is about 1 mi (1.6 km)nrtheast of the bridge and lies about 600 ft (200 m) south of the road.

Big Eric/s Crossing is a famous fishing spot on the HuronRiver, and Baraga County maintains a campground at the bridge.The river is high from late September until late May, so theoutcrops along the river are best visited during the middle andlate summer.

Sites 2 and 3 are on private land. However, so long as visitsare brief, and visitors continue to respect the surface and theexposures, property owners in the Upper Peninsula tend not topost their lands.
Pictured Rocks National Lakeshore, northern Michigan
Authors: Milstein Randall L.
Published: November 2007

Pictured Rocks National Lakeshore, T.48N., R.19W. andT.49N., R.13W., Alger County, Michigan; Munising, Wood IslandS. E., Grand Portal Point, Trappers Lake, Au Sable Point, Grand Sable Lake, and Grand Marais, Michigan, 7½-minuteQuadrangles. The Pictured Rocks National Lakeshore extendsfrom the city of Munising, Michigan, along the Lake Superiorshoreline 43 mi (69 km) to Grand Marais, Michigan (Fig. 1). Access to Pictured Rocks by automobile is either from Michigan 28 and Michigan 94 at Munising or Michigan 77 at Grand Marais. Access to the lakeshore can also be gained by hiking trails orboat. Commercial boat tours are available between June 1 andmid-October, weather permitting, and leave the harbor at Munising daily
The geology of the Niagara Escarpment, Fayette, Michigan
Authors: Dellapenna Timothy M.
Published: November 2007

Fayette State Park, the ghost town of Fayette, and an accessible portion of the Niagara Escarpment are located 8 mi (12.8 km) southwest of the town of Garden, Michigan, on the shore of Big Bay De Noc, Fayette7½–minute Quadrangle. The sites are reached by U.S. 2 to Garden, then south on Michigan M-183 to FayetteState Park (Fig. 1). The sites may also be reached by boat through entry into Snail Shell Harbor.
Ash Hollow State Historical Park
Authors: Diffendal R. F.
Published: November 2007

Ash Hollow State Historical Park, administered by the Nebraska Game and Parks Commission, is located primarily in Sec. 3, N½, Sec. 10, and the E½NE¼Sec.22, T.15N., R.42W. (Fig. 1), Garden County, Nebraska. The park and adjacent lands are shown on the Lewellen and Ruthton 7½ -minute Quadrangles; scale 1:24,000. U.S. 26 passes through the park. This highway and other paved roads provide access from 1-80. A camping area and a museum with excellent interpretive displays are located in the park.

Rock exposures are easily accessible by foot in the park and at road cuts along U.S. 26 and nearby county roads. No collecting of specimens is permitted in the park, but samples may be collected from road cuts. Fossils found by people in and near the park have been added to the museum collections. Poison ivy can be found in abundance in some parts of the area. Rattlesnakes may live anywhere in this part of Nebraska.
Middle Devonian Transverse Group in Charlevoix and Emmet counties, Michigan
Authors: Milstein Randall L.
Published: November 2007

The Middle Devonian Traverse Group is a sequence of carbonates and shales randomly exposed as shoreline bluffs, roadcuts, river gorges, and quarries in the northern portion of Michigan’s Southern Peninsula. Some of the most accessible of these outcrops are in Charlevoix and Emmet counties, where large sections of the group are exposed and are easily viewed bytraveling U.S. 31 north along the Lake Michigan shoreline (Fig. 1). The route defined in this chapter can be followed on the Charlevoix, Bayshore, and Petoskey, Michigan 15-minute quadrangles. Most locations described are situated on public lands. Visitors are urged to obtain permission quadrangles. Most locations described are situated on public lands. Visitors are urged to obtain permission prior to entering sites on private property.
Sleeping Bear Dunes National Lakeshore, Michigan
Authors: Milstein Randall L.
Published: November 2007

Sleeping Bear Dunes National Lakeshore, T.27 to 32N., R.13 to 16W., Benzie and Leelanau counties, Michigan;North Manitou, Maple City, Empire, and Frankfort, Michigan, 15-minute quadrangles. The Sleeping Bear Dunes National Lakeshore begins just north of Point Betsie in Benzie County and extends northward along theLake Michigan shoreline to Good Harbor Bay in Leelanau County (Fig.1). The national lakeshore also includes both North and South Manitou islands. Access to the national lakeshore by automobile is by Michigan 22. Access to the Manitou Islands is by private or charter boat service.Charter boat service is from Leland, Michigan, and is provided by Manitou Island Transit from June through December. Service is round trip once daily. Thedriving of vehicles in Sleeping Bear DunesNational Lakeshore is restricted to established, maintained roads. The driving of offroad recreational vehicles is restricted to designated roadways; offroad travel in sand dunes areas is prohibited.Pets are not allowed onthe Manitou Islands.
The Ledges of the Grand River, Michigan
Authors: Milstein Randall L.
Published: November 2007

The Ledges of the Grand River, T.4N., R.4W., Eaton County, Michigan; Eagle, Michigan, 7½-minute Quadrangle. The Ledges are located in the city of Grand Ledge, Michigan, 11 mi(18 km) west of Lansing, Michigan, on Michigan 43 (Fig. 1). The Ledges occupy both the northeast and southwest banks of the Grand River. Access to the southwest Ledges is by East Jefferson Street to Fitzgerald Park. Access is also possible either by canoe or the River Path Trail that begins at River and Harrisonstreets in Grand Ledge.
The Silurian reefs near Wabash, Indiana
Authors: Shaver Robert H.
Published: November 2007

The geology of the area in and near the City of Wabash, located in Wabash County along the upper Wabash River (Fig. 1), has had an important role in the development of modern concepts of Silurian sedimentation and reef growth in the southern Great Lakes area. The geologic significance of this area goes beyond an understanding of Silurian rocks in themselves, as Silurian reef studies have served as models in the development of fossil-reef and attendant sedimentation concepts throughout the geologic column.

One focal site is that of one of the best known fossil reefs in the world, The Wabash Reef, which is exposed on either side of the Wabash Railroad cut that extends more than 1, 000 ft (300 m) northeastward from the end of East Market Street and immediately northeast of the site of the former Big Four Railroad Station in Wabash (SE¼SE¼Sec.11, T.27N., R.6E., Wabash 7½-minute Quadrangle; Figure 1). Generations of geologists on scores of field trips have been inspired by this reef exposure. Noted leaders in the developing study of Silurian reefs who made oft-cited observations here, not all of them correct, include E. M. Kindle, Edgar R. Cumings, Robert R. Shrock, Marius LeCompte, and Heinz A. Lowenstam.

The exposure is on the property of the Wabash Railroad, a busy rail line. Permission generally is not required, but a local employee of the railroad usually inquires the business of a fieldtrip group on the site and allows the group to continue its
Cataract Lake emergency spillway, southwestern Indiana
Authors: Hasenmueller Walter A. , Bleuer N. K.
Published: November 2007

The Cataract Lake emergency spillway in Putnam County, Indiana, is in the SW¼NW¼ Sec.13, T.12N., R.5W. (Poland Quadrangle). The spillway cut is most easily reached by following the secondary road indicated in Figure 1 north from Indiana 42, a distance of about 2 mi (3.2 km). The secondary road thatleads to the spillway cut is identified by a Corps of Engineers sign that points the way to the reservoir dam. The intersection of Indiana 42 with the road to the spillway is about 5 mi (8 km) south of 1-70 and is 1.8 mi (3 km) east of Poland, Indiana, and 4.6 mi (7.4 km) west of the intersection of Indiana 243 and Indiana 42 (Fig. 1). The spillway cut is immediately adjacent to the secondary road that runs north from Indiana 42. Because the spillway cut is a restricted area, permission to enter should be obtained at the Corps of Engineers office just north of the dam.
The Indiana building-limestone district, south-central Indiana
Authors: Patton John B. , Carr Donald D.
Published: November 2007

The best public access to quarries from which the noted Indiana Limestone (trade name) is produced is at a park and demonstration center in the NE¼NW00BC;Sec.33, T.6N., R.1W., Lawrence County, Indiana (Oolitic 7½-minute Quadrangle), and lies 1 mi (1.6 km) north of Oolitic, which is, in turn, some 3 mi (4.8 km) north of Bedford, the county seat of Lawrence County (Fig. 1).

The site may be reached by passenger car or bus. Visitors approaching from the south by 4-lane Indiana 37 should pass the turnout to the north part of Oolitic and proceed 2.3 mi (3.7 km) to Trogden Lane, turning right (east) there and passing through Needmore to the old 2-lane route of Indiana 37(1.2 mi [1.9 km]). Turn right (southeast) and proceed half a mile (0.8 km) to the entry for the Indiana Limestone Tourist Park and Demonstration Center.

Visitors approaching from the north by Indiana 37 (4-lane)will pass a stoplight intersection with Indiana 45 at the southwest edge of Bloomington and proceed 7.7 mi (12.3 km) to the place where the road descends from the upland in a deep bedrock cut through the lower part of the Salem Limestone, the entire Harrodsburg Limestone and Ramp Creek Formation, and the upper few feet of the Borden Group (Middle Mississippian). The highway crosses Clear Creek about 0.3 mi (0.5 km) south of the cut, and 2.2 mi (3.7 km) south of the bridge the new highway intersects old Indiana 37 at a blinker light. Turn left
The Borden Group
Authors: Shaver Robert H.
Published: November 2007

One of many remarkable exposures of the Borden Group (lower Middle Mississippian) is on either side of a nearly continuous 1.5-mi (2.4-km) road cut along U.S. 50 leading downthrough the Knobstone Escarpment from the Knobs Overlook (aconvenient parking area for field-trip groups) in the northernthird of section 10 and central western part of section 14, T.5N., R.3E. (Medora and Kurtz 7½-minute Quadrangles), JacksonCounty, Indiana (Fig. 1). From the time of its earliest scientificnote by one of America’s great pioneer geologists (David DaleOwen in 1838), the wedge of Borden rocks, as much as 700 ft(210 m) thick in an area extending from central Illinois eastwardand southeastward into north-central Tennessee, has been intensivelystudied by scores of geologists.

Perhaps the two most significant of the earlier, pioneeringIndiana studies were conducted by Borden (1874) and Stockdale (1931). These and other studies of the time were preoccupiedwith descriptive explorations and with establishing ages of theBorden divisions within the Subcarboniferous Group, a term thatOwen had correctly applied about 150 years ago. Only during amodern period of intensive study in the broader area noted abovedid geologists come to realize that the Borden Group is a sperbexample of a vast ancient delta system complete with bottomset, foreset, and topset beds together with many sedimentologic faciesand ecologic niches afforded by prodelta, delta-slope, deltaplatform, distributary-channel, and interdistributary-flat environments.(See, for example: Swarm and others, 1965; Lineback, 1966;Suttner and Hattin, 1973; Kepferle, 1977; Gray, 1979
Madison, Indiana
Authors: Totten Stanley M. , Hay Helen B.
Published: November 2007

The Madison area in southeastern Indiana has long beenacclaimed for its geomorphic features, Upper Ordovician fossils, and scenic beauty. Madison is located on the Ohio River (Figure1) almost midway between Cincinnati, Ohio, and Louisville, Kentucky. [t is easily accessible by several state highways, and theU.S. 421 bridge over the Ohio River at Madison providesaccess from Kentucky. Clifty Falls State Park offers outstandingrecreational and camping facilities. Madison actually consistsof two towns separated from each other by a 300 ft (90 m)-high rocky bluff: so-called Historical Madison located on theterraces and floodplain and the newer North Madison located onthe upland.

Upper Ordovician and Silurian strata, well exposed in theMadison area along numerous road cuts and tributaries of theOhio River, dip gently westward along he western flank of theCincinnati Arch and the eastern margin of the Illinois Basin. Thebest and most easily accessible outcrops are along U.S. 421 justnorth of Madison where the highway rises from the Ohio Rivervalley to the uplands.

The fossiliferous Ordovician outcrops at Madison areamong the classic Cincinnatian fossil-collecting localities ofsoutheastern Indiana, southwestern Ohio, and northern Kentucky.In addition, the distinctive dolomitic and sparsely fossiliferousSaluda Formation near the top of the Ordovician is wellexposed and reaches its maximum thickness in the Madison area. A roadlog at the end of this article and keyed to Figure 1describes access to the many points of geologic interest in theMadison area. Important vantage points are shown by letters in Figure 1.
Sub-Pennsylvanian disconformity near Shoals, Indiana
Authors: Gray Henry H.
Published: November 2007

This site is along a spur railroad cut in the W½NE¼Sec. 28, T.3N., R. 3W., Martin County, Indiana (Fig. 1). It is shown on theHuron 7½-minute Quadrangle and is accessible by foot from acounty road that crosses the railroad just south of the cut. The cutis on the property of the National Gypsum Company, Shoals Plant, and permission to visit should be requested, particularly forgroups.

This is the best and most revealing exposure of the sub-Pennsylvanian disconformity in southern Indiana and is one ofthe best in the entire Illinois Basin. A small pre-Pennsylvanianvalley with about 50 ft (15 m) relief is well shown, and manyfeatures of the rocks above and below the contact are also illustrated. This is an excellent introduction to the stratigraphy ofmuch of southwestern Indiana.
The Late Cretaceus Niobrara Formation in south central Nebraska
Authors: Pabian Roger K.
Published: November 2007

Excellent outcrops of Niobrara and Pleistocene strata can be seen near Franklin and Bloomington (Exposures 1 and 2, Fig. 1; Figs. 2-5) in Franklin County. The Niobrara Formation generally dips westward at about 15 ft/mi (3 m/km), and at the western end of the outcrop area in Harlan County, the Niobrara is conformably overlain by the Pierre Shale.

All of the outcrops are road cuts and are within public access. The outcrop near Franklin has a very steepnorth slope and a fairly gentle east slope. The section at the Bloomington bridge is very steep but negotiable by persons without physical limitations. The outcrops near Red Cloud are fairly steep but are also negotiable by persons without physical limitations.
Kelleys Island
Authors: Feldmann Rodney M. , Bjerstedt Thomas W.
Published: November 2007

Kelleys Island is the easternmost of the Lake Erie Islands group, located north of Marblehead Peninsula and Sandusky, Ohio, (Fig. 1) on the Kelleys Island 7½-minute Quadrangle. Access to the Island is provided by the Newman Boat Lines which operates a ferry from Marblehead (April through November) and from Sandusky (June through Labor Day). Throughout the year, the Island is also served by Island Arilines from Port Clinton Municipal Airport. On the Island, transportation is available in the form of rental bicycles, golf carts, or private cars ferried from the mainland.
Garfield Heights
Authors: Miller Barry B. , Szabo John P.
Published: November 2007

Complex Quaternary deposits are well exposed alongthe west of McCracken Road. The pit has been used asa landfill valley of Mill Creek, in Garfield Heights (Shaker Heights 7½- through the years and is now partof an industrial park. A major minute Quadrangle), Cuyahoga County, Ohio (Fig. 1).Details of interstate highway, 1-480 (Fig. 1), passes through and partially the stratigraphy can be examined best at two sections exposed covers some of the units that were previously exposed in the along the steep-wall of an abandoned sand and gravel pit north-steep-wall just southeast of McCracken Road. Access to the northwest pit may be made through an entrance road to the industrial park, which joins the northwestern side of McCracken Road about 100 ft (30 m) southwest of the intersection of the Conrail right-of-way and McCracken Road. Vehicles should be parked close to the steep-wall of the pit and as far as possiblefrom buildings in the industrial park.
Wellsville Hill
Authors: Wiese Robert G.
Published: November 2007

Ohio 7 is a divided highway with wide shoulders adequate for parking at the exposures. Access to the area from western Penn-The Wellsville Hill section consists of two large roadcuts sylvania and West Virginiais by bridges across the Ohio River at located along Ohio 7 just south of Wellsville, Ohio, on the East Liverpool, Ohio, to the north and at Steubenville, Ohio, to Wellsville Ohio-West Virginia 7½-minute Quadrangle (Fig. 1). the south of the field area.
Black Hand Gorge State Nature Preserve
Authors: Malcuit Robert J. , Bork Kennard B.
Published: November 2007

Abstarct

Black Hand Gorge State Nature Preserve is located about 9 mi (15 km) east of Newark, Ohio. It is readily accessible from Ohio 16 and 146, as shown on Figure 1. The area became a state nature preserve in 1975 and is accessible on a year-round basis during daylight hours. Canoeing in the river and bicycling along a recently constructed bicycle trail are possible when weather and water level permit. The gorge is located on the west-central area of the Toboso (Ohio) 7½-minute Quadrangle (Fig. 2).
John Bryan State Park, Ohio
Authors: Ausich William I.
Published: November 2007

Abstarct

John Bryan State Park is located 3 mi (4.8 km) southeast of Yellow Springs, Ohio. Outcrops are highwall exposures of a gorge cut by the Little Miami River (Fig.1). Access to the two sections in John Bryan State Park is by foot trails on either side of the Little Miami River. The trails originate from the lower picnic area parking lot. A foot bridge spans the Little Mii 0.25 mi (0.4 km) east of the lower picnic area parking lot. The North Section is beneath a waterfall and in a stream bed 0.5 mi (0.8 km) east of the bridge along the north river trail, and the South Section is beneath a waterfall and in a stream bed 0.25 mi (0.4 km) east of the bridge along the south river trail. Locations are as follows: North Section, NW¼ SW¼ NW¼ Sec. 1, T.4, R.8; South Section, SE¼ NW¼ SE¼ Sec. 1, T.4, R.9; both sites on Clifton U.S.G.S. 7½-minute Quadrangle, Greene County, Ohio (Fig. 1).
Geologic highlights of an Archean greenstone belt, western Vermilion district, northeastern Minnesota
Authors: Southwick D. L.
Published: November 2007

The western Vermilion district is located in northeastern Minnesota, about 18 mi (30 km) north of the towns of Virginia and Aurora on the Mesabi iron range (Fig.1). The major towns in the western Vermilion district are Cook, Tower, Soudan, and Ely. The area to be described here lies within the Tower and Soudan 7¼-minute Quadrangles (Fig. 1).
Plateau basalts of the Keweenawan North Shore Volcanic Group
Authors: Green John C.
Published: November 2007

Three specific outcrop areas are included: (1) Lakewood, 2.1mi (3.5 km) northeast of the Lester River (in Duluth, Minnesota)on St, Louis County 61 (S¼ Sec. 34, T.5lN., R.13 W.; Lakewood7¼-minute Quadrangle), in Congdon (city) Park; (2) Two Harbors,0.5 mi (0.8 km) south of U.S. 61 on First Street(NW½ Sec. 6, T. 52N., R. 10W.; Two Harbors 7¼-minute Quadrangle), in Burlington Bay(city) Tourist Park, and (3) GooseberryFalls, 13.5 mi (23 km) northeast of Two Harbors on U.S. 61(SW½ Sec. 22, T. 54N., R. 9W., Split Rock Point 7½-minute Quadrangle), in Gooseberry Falls State Park. Note: State Park rules prohibit defacing or collecting rocks. Removal of bedrock specimens showing the special structures in all areas is strongly discouraged for the benefit of future observers.
The Middle Proterozoic Duluth Complex at Duluth, Minnesota
Authors: Green John C.
Published: November 2007

The Duluth Complex underlies an area of approximately 2,265 mi2 (6500 km2), but over much of its extent it is covered by glacial deposits. Some of the best and most representative exposures are in the city of Duluth. Several outcrops are described here along the Skyline Parkway, a well-marked scenic road near the top of the slope on which Duluth is built, facing the Lake Superior Basin. They are in the West Duluth, Duluth Heights, and Duluth 7½-minute Quadrangles. The first stop is adjacent to I-35 just southwest of Duluth (Fig. 1).
Jay Cooke State Park and Grandview areas
Authors: Jirsa M. A. , Morey G. B.
Published: November 2007

Jay Cooke State Park occupies nearly 15 mi2 (38 km2) in the northeastern corner of Carlton County in T.48N., R.15 and 16W. (Fig. 1). It is about midway between the village of Thomson and Fond du Lac, the westernmost suburb of Duluth. The park may be reached by following Minnesota 210 from the Carlton-Cromwell interchange with I-35 eastward for approximately 3.5 mi (6 km) through the town of Carlton to the St. Louis River. Immediately after crossing the river at Thomson, the highway turns sharply to the south and 0.1 mi (0.2 km) later enters Jay Cooke State Park (Fig. 2). The Park Headquarters, a picnic area, and an information building are located approximately 2 mi (3.4 km) intothe park. As with all Minnesota state parks, a daily fee or a yearly permit is required to use the park facilities. Minnesota 210 continues through the park along the north side of the St. Louis River for an additional 5.5 mi (9.3 km) where it joins Minnesota 23 in Fond du Lat.
Pipestone National Monument
Authors: Morey G. B. , Setterholm Dale R.
Published: November 2007

Pipestone National Monument is located in parts of sections 1 and 2, T.106N., R.46W., north of the City of Pipestone, Pipestone County, southwestern Minnesota (Fig. 1). The monument is located 0.9 mi (1.5 km) northwest of the intersection of U.S. 75 and Minnesota 23. Proceed north on U.S. 75 for 0.4 mi (0.7 km); turn west and follow monument signs 0.5 mi (0.8 km) to the entrance. As with all national parks and monuments, no samples may be collected without a permit from the Department of Interior, U.S. National Park Service.
Precambrian Sioux Quartzite at Gitchie Manitou State Preserve, Iowa
Authors: Anderson Raymond R.
Published: November 2007

Gitchie Manitou State Preserve is located in the northwesternmost corner of Iowa, in the W½, Sec. 11, T. 100N., R. 49W., about 9 mi (14,5 km) northwest of Larchwood in Lyon County, Iowa (Fig. 1). The preserve is situated in the valley of the Big Sioux River, which forms the western limits of the preserve and the boundary between Iowa and South Dakota. The highest elevation within the preserve is about 1,286 ft (392 rlevel, about 40 ft (12 m) above river level but about below the elevation of nearby upland areas.