Silver Star Mountain | |
---|---|
Highest point | |
Elevation | 4,364 ft (1,330 m) NAVD 88 [1] |
Prominence | 1,480 ft (450 m) |
Coordinates | 45°44′51.8″N122°14′20.5″W / 45.747722°N 122.239028°W [1] |
Geography | |
Location | Skamania County, Washington, U.S. |
Parent range | Cascade Range |
Topo map | USGS Bobs Mountain |
Geology | |
Volcanic arc | Cascade Volcanic Arc |
Silver Star Mountain is a recently uplifted ridge of older Western Cascades volcanic rock, underlain by a granitic pluton of similar Western Cascades age, located in the Cascade Range in the U.S. state of Washington. (contrary to local legend, the mountain is not an "extinct volcano," but rather the uplifted debris and roots of a number of very old volcanic vents) Consisting of late Eocene to Oligocene epoch rock, it lies within the Gifford Pinchot National Forest. Silver Star is composed of three lithologic units (distinct units of rock, each with different physical characteristics), including the large Silver Star Granodiorite unit.
Silver Star Mountain and the surrounding area, in contrast to the rest of the local backcountry, has a ridge-like appearance, creating a striking skyline similar to mountains further north in the Cascade Range. The area lacks trees, and comprises steep cliffs, talus slopes, and meadows filled with wildflowers. The mountain can be hiked and has been noted for its trails by local mountaineers.
Silver Star Mountain lies in Skamania County, in the U.S. state of Washington. [2] According to the North American Vertical Datum of 1988, it reaches an elevation of 4,364 feet (1,330 m), [1] though the Geographic Names Information System database lists its elevation at 4,377 feet (1,334 m), [2] and The Columbian gives its height as 4,382 feet (1,336 m). [3] The mountain lies in the western segment of the Middle Cascades. [4] It is about 12 miles (19 km) north of the western end of the Columbia River Gorge and is accessible from United States Forest Service roads connected to county roads and Washington state highways. [4] Silver Star is located in the southwestern corner of the Gifford Pinchot National Forest, which encompasses an area of 1,300,000 acres (5,300 km2) in southwestern Washington state. [3]
The greater Silver Star Mountain area consists of an eroded plateau, largely made up of lava, with an average relief of about 2,000 feet (610 m) and reaching a local maximum elevation of 3,000 feet (910 m). [5] Unlike the rest of the western Cascade backcountry, [3] it has a ridge-like appearance, creating a striking skyline similar to mountains further north in the Cascade Range. [6] The area lacks trees and comprises steep cliffs, talus slopes, and meadows filled with wildflowers. [3]
The locale drains into the Washougal River and the Lewis River's East Fork, which flow to the south and west respectively. Erosion by these rivers has dissected the land, producing a relief of 2,500 to 3,000 feet (760 to 910 m). [4] Precipitation reaches a peak during the winter season, usually deposited as snow that produces drifts, especially in deep canyons in the area. These drifts often remain until the summer, feeding small streams in the vicinity. Surface runoff has increased due to the removal of forest cover by historical fires, including large fires in 1902 and 1929. As a result, runoff has eroded gullies on local slopes and increased removal of soil. [4] However, there are talus slopes with heights up to 1,200 feet (370 m), which cover a large percentage of the granodiorite. [5] The granodiorite is not exposed at the summit or along main approach trails. Small cirque-like basins, likely carved out by small glaciers, occur in a few of the larger canyons, with depressions up to 75 feet (23 m) in depth. These often host tarn lakes, and some support snowdrifts. [6]
Soil on and around the mountain has been eroded by repeated fires, including the Yacolt Burn in 1902 and 16 additional fires through 1929. Slow regrowth motivated the Civilian Conservation Corps to plant more trees during the 1930s, [7] and terracing was also used during the 1960s to facilitate better vegetation regrowth. [8]
Wildflowers grow at unusually low elevations at Silver Star Mountain, as a result of fires, wind, and rocky subsoil. [9] There are more than 100 types of wildflowers and flowering shrubs on the volcano, such as heather, star tulip, tiger lily, Grey's loveage, hairbell, bear grass, western bistort, columbine, Avalanche lily, broadleaf lupine, wooly sunflower, Cardwell's penstemon, Indian paintbrush, [9] phlox, balsamroot, and glacier lilies. [3] Trails around the mountain, in addition to offering views of wildflower-cover slopes, pass through thickets of huckleberry, [10] as well as forests with noble fir. [8]
In the area surrounding Silver Star Mountain, rocks forms three discrete lithologic units (characterized by visible physical characteristics or the gross physical character of the rock). The Eagle Creek formation is the oldest, likely dating to the Oligocene epoch (or the lower Miocene). [6] The rock consists mostly of cream-colored, vitric tuffs, which have undergone weathering that has converted them to a yellow or white colored soil, though there are also multicolored tuffs, which vary from red to green and purple breccias. [11] Often their color depends on the extent of inner iron compounds. [12] They display little assortment or bedding, indicating that they likely accumulated subaerially. [11] Rocks from the formation form outcrops on the eastern part of the Silver Star Mountain locale, and are exposed in central parts of the Columbia River Gorge. [6] Other exposures from the Eagle Creek formation can be observed in Silver, Bluebird, and Bear creeks, where they occur in canyons along the eastern part of the locale. [11] The second, younger unit is the Skamania Andesites, which sit atop the Eagle Creek deposits and consist of thick layers of andesite interbedded with minor inclusions of breccia and pyroclastic material. Less exposed than the Eagle Creek deposits, they are often detectable within 5 feet (1.5 m) of the surface, sitting disconformably over the Eagle Creek rock layers as a result of thorough erosion. At other points, including the eastern border of the Silver Star area, they occur between layers of the Eagle Creek tuffs, possibly due to partially overlapping deposition times or the combination of the tuff deposition and andesite extrusion. [11] The Skamania Andesites encompass the largest distribution of the three lithologic formations in the area, forming thin lava flows that suggest extrusion as highly fluid lava. [11] Andesites located higher on the Silver Star Mountain edifice have undergone less erosion than deposits at lower elevations. [13] The age of the Skamania Andesites is not known, though Felts (1939) hypothesized that they were formed during the pre-middle Miocene epoch. [13] They have a gray to green-gray color and are porphyritic, containing smaller amounts of breccia and tuff, as well as phenocrysts with plagioclase, augite, and magnetite. The phenocrysts range from 0.039 to 0.236 inches (1 to 6 mm) in size, with an average diameter of 0.12 inches (3 mm). Sometimes, they contain chlorite or similar minerals. [12] Rocks from the upper third of the Skamania Andesites have a similar composition, but they are more vesicular in texture. [14]
The third unit is called the Silver Star Granodiorite, [15] which is made up of augite diorite and quartz diorite. [16] Dikes with quartz, tourmaline, and sericite occur within the mass, which has a light color aggregated from white to pink plagioclase with orthoclase, clear quartz, and black to green biotite and hornblende crystals. [17] About 10 miles (16 km) in length and ranging from 1.5 to 2.5 miles (2.4 to 4.0 km) in width, the stock (a small pluton) lies along a long axis angled at twenty degrees to the east. It has steep walls which have not been excavated by local canyons that cut into nearby rock. [16] Felts (1939) suggested that the stock intruded at an angle of 20 degrees east of north. [18] The stock cuts through the Eagle Creek formation and the lower two-thirds of the Skamania Andesites, forming contact metamorphic rock and small dikes of granodiorite and aplite into their tuff and andesite deposits. The absence of dikes or intrusions in the upper third of the Skamania Andesites formation suggests a time gap between the extrusion of the lower and upper segments, during which the granodiorite intrusion occurred. [16] The granodiorite has been altered to create talus, and there are few outcrops, which only occur at stream bottoms and rarely at cliffs that have not been covered with talus. [16] Lava flows from several more modern sources, likely Pleistocene, were deposited in the Lewis River canyon 4 miles (6.4 km) to the west of the Silver Star Mountain and in the Wind River canyon to the east. [13]
Silver Star Mountain consists of late Eocene epoch to Oligocene epoch rock, particularly calc-alkaline volcaniclastic sediment, from a number of unidentified volcanic vents. These rock formations were intruded on the mountain's eastern side by the Silver Star intrusion, a deep stock of granodiorite and quartz diorite that also formed small deposits of copper in the area. Calc-alkaline volcaniclastic sediments, referred to as the Skamania Volcanics, lie nearby and are overlapped by the Troutdale Formation. During the Miocene epoch, these deposits formed hills to the north of the major Columbia River valley, with sufficient height to prevent flooding. [19]
The intrusion of the Silver Star stock produced small deposits of gold, zinc, copper, zeolites, quartz and calcite in the surrounding country rock. Per the Skamania County Soil Survey, small abandoned gold mines can be found in creek bottoms throughout the area. E.A. Dole, an early settler, struck silver near the mountain in 1874. He named the mine Silver Star Quartz Ledge. The ore gathered was assayed at 41.17 silver and 63.72 lead per ton. [20] Granite has been documented near the foot of the mountain, about 15 miles (24 km) northeast of the city of Washougal. [21] The intrusion produced at least one dike of granodiorite, which sits nearby. [22] Much of the local soil formed from granodiorite deposits and volcanic ash. [23]
A number of ditches near Silver Star Mountain known as the Indian Pits can be seen on one of the trails, which is known as the Indian Pits Trail #180E. These ditches also occur in other parts of the Columbia River Gorge area. Archaeologists debate the purpose of these pits, though three prominent hypotheses have emerged. One states that the pits were built by Native Americans to seek spiritual visions, while another claims that the pits served as blinds for hunting mountain sheep and goats fleeing cougars or wolves down local talus slopes or other hunters in brush below. The third hypothesis theorizes that the pits were used to store food. [24]
The September 1902 [25] Yacolt Burn started as a slash fire near the city of Stevenson. Spread by a strong, eastward blowing wind, it burned forest for 30 miles (48 km), reaching the town of Yacolt and killing 38 people. [7] The fire encompassed close to 239,000 acres (970 km2) of land across southwest Washington state, including parts of Clark, Cowlitz, and Skamania counties. [25] 16 smaller fires followed in the next few decades, prompting government agencies to build a fire lookout on Silver Star, [7] on the higher north peak known as "Star L.O.", which was installed in 1952, but was removed by 1969. [1] The Yacolt Burn State Forest was named after the 1902 fire. [25]
The Silver Star Mountain area is lightly used for hiking. [26] The Silver Star trail runs 5 miles (8.0 km) to an old roadbed located west of Silver Star Mountain, while the Silver Star Summit Trail #180D, 0.25 miles (0.40 km) long, reaches the summit of Silver Star Mountain. Indian Pits Trail #180E and Pyramid Rock Trail #180F branch off the Silver Star Trail to the south of Silver Star Mountain. [10] From Ed's Trail #180A, [27] named after Edward Robinson, one of the pioneers of the Chinook Trail Association, [28] hikers can see views of nearby volcanoes, including Mount St. Helens, Mount Rainier, Mount Adams, Mount Hood, and Mount Jefferson on particularly clear days. [27] This has been described by local hikers as one of the best hikes in Washington state, [29] [30] only gaining about 1,200 feet (370 m) in elevation between the Silver Star and Ed's Trails. [3] Trail #172 Bluff Mountain offers views of the Vancouver and Portland metropolitan area. [8]
The trail area is administered by the United States Forest Service, and the Mount Adams Ranger District serves as its information center. [26] A number of the trails were built by and are still maintained by the Chinook Trails Association. [27] [31]
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It lies 52 miles (83 km) northeast of Portland, Oregon, and 98 miles (158 km) south of Seattle. Mount St. Helens takes its English name from that of the British diplomat Alleyne Fitzherbert, 1st Baron St Helens, a friend of explorer George Vancouver who surveyed the area in the late 18th century. The volcano is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire.
Mount Jefferson is an inactive stratovolcano in the Cascade Volcanic Arc, part of the Cascade Range in the U.S. state of Oregon. The second highest mountain in Oregon, it is situated within Linn County, Jefferson County, and Marion County and forms part of the Mount Jefferson Wilderness. Due to the ruggedness of its surroundings, the mountain is one of the hardest volcanoes to reach in the Cascades. It is also a popular tourist destination despite its remoteness, with recreational activities including hiking, backpacking, mountaineering, and photography. Vegetation at Mount Jefferson is dominated by Douglas fir, silver fir, mountain hemlock, ponderosa pine, lodgepole pine, and several cedar species. Carnivores, insectivores, bats, rodents, deer, birds, and various other species inhabit the area.
Mount Washington is a deeply eroded volcano in the Cascade Range of Oregon. It lies within Deschutes and Linn counties and is surrounded by the Mount Washington Wilderness area.
Mount McLoughlin is a dormant steep-sided stratovolcano, or composite volcano, in the Cascade Range of southern Oregon and within the United States Sky Lakes Wilderness. It is one of the volcanic peaks in the Cascade Volcanic Arc, within the High Cascades sector. A prominent landmark for the Rogue River Valley, the mountain is north of Mount Shasta, and south-southeast of Crater Lake. It was named around 1838 after John McLoughlin, a Chief Factor for the Hudson's Bay Company. Mount McLouglin's prominence has made it a landmark to Native American populations for thousands of years.
Indian Heaven is a volcanic field in Skamania County in the state of Washington, in the United States. Midway between Mount St. Helens and Mount Adams, the field dates from the Pleistocene to the early Holocene epoch. It trends north to south and is dominated by six small shield volcanoes; these shields are topped by small spatter and cinder cones, and the field includes a number of subglacial volcanoes and tuyas. The northernmost peak in the field is Sawtooth Mountain and the southernmost is Red Mountain; its highest point is Lemei Rock at an elevation of 5,925 feet (1,806 m).
Goat Rocks is an extinct stratovolcano in the Cascade Range, located between Mount Rainier and Mount Adams in southern Washington, in the United States. Part of the Cascade Volcanoes, it was formed by the subduction of the Juan de Fuca Plate under the western edge of the North American Plate. The volcano was active from 3.2 million years ago until eruptions ceased between 1 and 0.5 million years ago. Throughout its complex eruptive history, volcanism shifted from silicic explosive eruptions to voluminous, mafic activity.
Broken Top is a glacially eroded complex stratovolcano. It lies in the Cascade Volcanic Arc, part of the extensive Cascade Range in the U.S. state of Oregon. Located southeast of the Three Sisters peaks, the volcano, residing within the Three Sisters Wilderness, is 20 miles (32 km) west of Bend, Oregon in Deschutes County. Eruptive activity stopped roughly 100,000 years ago, and erosion by glaciers has since reduced the volcano's cone to where its contents are exposed. There are two named glaciers on the peak, Bend and Crook Glacier.
The Yacolt Burn is the collective name for dozens of fires in Washington state and Oregon occurring between September 8 and September 12, 1902, causing 38 deaths in the Lewis River area, at least nine deaths by fire in Wind River and 18 deaths in the Columbia River Gorge.
The Three Sisters are closely spaced volcanic peaks in the U.S. state of Oregon. They are part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Washington and Oregon to Northern California. Each over 10,000 feet in elevation, they are the third-, fourth- and fifth-highest peaks in Oregon. Located in the Three Sisters Wilderness at the boundary of Lane and Deschutes counties and the Willamette and Deschutes national forests, they are about 10 miles south of the nearest town, Sisters. Diverse species of flora and fauna inhabit the area, which is subject to frequent snowfall, occasional rain, and extreme temperature variation between seasons. The mountains, particularly South Sister, are popular destinations for climbing and scrambling.
Black Butte is an extinct stratovolcano in the U.S. state of Oregon. Located in Jefferson County, it is part of Deschutes National Forest. Black Butte forms part of the Cascade volcanic arc. The butte lies just south of the Metolius Springs, which merge to form the headwaters of the Metolius River. The Metolius River's basin sustains a wide array of plant life, large and small mammals, and more than 80 bird species.
Larch Mountain, elevation 3,480 feet (1,060 m), is the highest free-standing peak in Clark County, Washington. It is laced by a network of gravel roads as part of the Yacolt Burn State Forest. The eastern flank of the mountain was scorched by a gigantic forest fire in September 1902 and subsequently experienced a massive rockslide that rendered that side mostly unvegetated. The southern section of the mountain is part of the Jones Creek Off-Road Vehicle recreation area. From the picnic area at the top, the view is west toward the Vancouver, Washington area and east to Silver Star. A minimum security prison/work camp is situated nearby, whose inmates construct fire roads, fire trails, maintain campgrounds and help fight fires in the area.
Diamond Peak is a volcano in Klamath and Lane counties of central Oregon in the United States. It is a shield volcano, though it might also be considered a modest stratocone. Diamond Peak forms part of the Cascade Volcanic Arc, a segment of the Cascade Range in western North America extending from southern British Columbia through Oregon to Northern California. Reaching an elevation of 8,748 feet (2,666 m), the mountain is located near Willamette Pass in the Diamond Peak Wilderness within the Deschutes and Willamette national forests. Surrounded by coniferous forest and visible in the skyline from foothills near Eugene, Diamond Peak offers a few climbing routes and can be scrambled. Diamond Peak is one of Oregon's Matterhorns.
The Boulder Creek Wilderness is a wilderness area located in the Umpqua National Forest in the southern Cascade Range of Oregon, United States. It was designated by the United States Congress in 1984 and comprises 19,100 acres (7,729 ha).
The Mount Jefferson Wilderness is a wilderness area located on and around Mount Jefferson in the central Cascade Range of Oregon in the United States. The wilderness lies within the Willamette National Forest and Deschutes National Forest. The wilderness area covers 111,177 acres (449.92 km2), with more than 150 lakes. It also has 190 miles (310 km) of trails, including 40 miles (64 km) of the Pacific Crest National Scenic Trail. Three Fingered Jack and Mount Jefferson are both prominent features of the wilderness area. Mount Jefferson Wilderness is the second most visited Oregon wilderness area after the Three Sisters Wilderness.
West Crater is a small lava dome with associated lava flows in southern Washington, United States. Located in Skamania County, it rises to an elevation of 4,131 feet (1,259 m), and forms part of the Cascade Volcanic Arc. It is also part of the Marble Mountain-Trout Creek Hill volcanic field, a little-known Quaternary volcanic field in the southern Cascades of Washington state. The area can be hiked, and can be accessed by roads in the Gifford Pinchot National Forest.
Olallie Butte is a steep-sided shield volcano in the Cascade Range of the northern part of the U.S. state of Oregon. It is the largest volcano and highest point in the 50-mile (80 km) distance between Mount Hood and Mount Jefferson. Located just outside the Olallie Scenic Area, it is surrounded by more than 200 lakes and ponds fed by runoff, precipitation, and underground seepage, which are popular spots for fishing, boating, and swimming. The butte forms a prominent feature in the Mount Jefferson region and is usually covered with snow during the winter and spring seasons.
Hayrick Butte is a tuya, a type of subglacial volcano, in Linn County, Oregon. Located in the Willamette National Forest near Santiam Pass, it lies adjacent to the cinder cone Hoodoo Butte, which has a ski area. Hayrick Butte likely formed when lava erupted underneath an overlying glacier or ice sheet, producing the flat top with near-vertical walls along the ice-contact margin as the lava cooled and hardened. Hayrick Butte has a nearly flat plateau about 0.5 miles (0.80 km) across and steep walls rising about 700 feet (0.21 km) above its surroundings. A cartographer accidentally switched the names for nearby Hoodoo Butte and Hayrick Butte; the word "hoodoo" usually refers to rock piles and pinnacles like those observed at Hayrick Butte.
Black Crater is a shield volcano in the Western Cascades in Deschutes County, Oregon. Located near McKenzie Pass, the volcano has a broad conical shape with gentle slopes. The volcano likely formed during the Pleistocene and has not been active within the last 50,000 years. Eruptive activity at the volcano produced mafic lava flows made of basaltic andesite and olivine basalt; it also formed a number of cinder cones. A normal fault occurs on the western side of the volcano, trending north–south. The volcano has been eroded by glaciers, which carved a large cirque into the northeastern flank of the mountain, forming its current crater.
Trout Creek Hill is a small Pleistocene basaltic shield volcano in Washington, United States. Located in Skamania County, Trout Creek Hill rises to an elevation of 2,946 feet (898 m). It is part of the Cascade Volcanic Arc, located in the Marble Mountain-Trout Creek Hill volcanic field.
The East Fork Lewis River is a river in the state of Washington in the United States. It is the largest tributary of the Lewis River. Its source is on Green Lookout Mountain in Skamania County. It then flows to the west through Clark County until it converges with the Lewis about 3.5 mi (5.6 km) upstream from the Columbia River.
Media related to Silver Star Mountain (Skamania County, Wash.) at Wikimedia Commons