 = Boise National Forest = 
 
 Boise National Forest is a <unk> protected area covering 2 @,@ 203 @,@ 703 acres ( 8 @,@ 918 @.@ 07 km2 ) of the U.S. state of Idaho as part of the national forest system . <unk> on July 1 , 1908 from part of Sawtooth National Forest , it is managed by the U.S. Forest Service as four units : the Cascade , Emmett , Lowman , and Mountain Home ranger districts . 
 The Idaho Batholith <unk> most of Boise National Forest , forming the forest 's Boise , Salmon River , and West mountain ranges ; the forest reaches a maximum elevation of 9 @,@ 730 feet ( 2 @,@ 970 m ) on Steel Mountain . Common land cover includes sagebrush steppe and spruce @-@ fir forests ; there are 9 @,@ 600 miles ( 15 @,@ 400 km ) of streams and rivers and 15 @,@ 400 acres ( 62 km2 ) of lakes and reservoirs . Boise National Forest contains 75 percent of the known populations of <unk> 's <unk> , a flowering plant endemic to Idaho . 
 The Shoshone people occupied the forest before European settlers arrived in the early 1800s . Many of the early settlers were trappers and prospectors before gold was discovered in 1862 . After the 1860s Boise Basin gold rush ended , mining of tungsten , silver , antimony , and gold continued in the forest until the mid @-@ twentieth century . Recreation opportunities and facilities include over 70 campgrounds , whitewater and <unk> boating , cabin rentals , and 1 @,@ 300 miles ( 2 @,@ 100 km ) of trails for hiking , <unk> , horseback riding , and <unk> off @-@ road vehicle use . The Forest Service has an objective to maintain timber , range , water , recreation , and wildlife for multiple use and sustained yield of its resources . 
 
 = = History = = 
 
 Archaeological evidence indicates that human habitation in Idaho began towards the end of the last ice age : bone fragments about 10 @,@ 000 years old have been found in Wilson <unk> Cave , an <unk> cave on the Snake River Plain believed to have been occupied by indigenous people until as recently as the 17th century . A change of climate around 7000 years ago dried up much of the Great Basin , forcing the Shoshone people northward into the mountainous areas of central Idaho . Most of what is now Boise National Forest was sparsely inhabited by Native Americans , and several archaeological sites , including <unk> , rock shelters , burial grounds , and <unk> have been found along rivers in the area . <unk> and fur traders of European descent first arrived in the area in the early 1800s , starting with John Jacob Astor 's Pacific Fur Company in October 1811 . Donald Mackenzie and <unk> Payette trapped in the area of Boise National Forest in 1819 . By 1840 the fur trade was coming to an end , but the westward migration on the Oregon Trail , which passed south of the forest , was beginning . The first settlers moved into the mountains in the 1860s after gold was discovered in Idaho , which forced many of the Shoshone out and led to conflicts throughout the state , including the <unk> War in southern Idaho . 
 <unk> George Grimes and Moses <unk> were the first to discover gold in the forest at the eponymous Grimes Creek on August 2 , 1862 . Subsequent gold discoveries at Rocky Bar in 1863 and Atlanta in 1864 increased the rush of people to Idaho , and in 1863 Idaho City , with a population of 6 @,@ 267 , surpassed Portland , Oregon as the largest city in the Pacific Northwest . The Idaho gold rush was largely over by 1870 , and the population of the Boise Basin fell from 16 @,@ 000 to 3 @,@ 500 . In 1898 the forest 's first gold dredge was built in <unk> and followed by several others . By 1951 when the last dredges shut down , at least 2 @.@ 3 million ounces ( 65 @.@ 2 million grams ) of gold had been produced from the Boise Basin area . Silver was mined along the Crooked River from 1882 until 1921 , but a silver mine at Silver Mountain proved unsuccessful . Following a shortage of mercury during World War II , mines in the <unk> area became the country 's largest producer of tungsten and second largest source of mercury . The most important known <unk> deposit of niobium and tantalum in the United States is located in Bear Valley . From 1953 until 1959 dredges there produced $ 12 @.@ 5 million ( $ 101 million today ) in niobium , tantalum , and uranium . Other minerals mined in the forest include antimony and <unk> . 
 
 = = = U.S. Forest Service = = = 
 
 Boise National Forest was created on July 1 , 1908 from part of Sawtooth National Forest , and originally covered 1 @,@ 147 @,@ 360 acres ( 4 @,@ <unk> @.@ 2 km2 ) . The U.S. President was given the authority to establish forest reserves administered by the U.S. Department of the Interior by the Forest Reserve Act of 1891 . With the passage of the Transfer Act of 1905 , forest reserves were transferred to the U.S. Department of Agriculture in the newly created U.S. Forest Service . Present @-@ day Boise National Forest was first protected as part of two forest reserves by <unk> issued by President Theodore Roosevelt : Sawtooth Forest Reserve ( created on May 29 , 1905 and expanded on November 6 , 1906 ) and Payette Forest Reserve ( created on June 3 , 1905 ) . After forest reserves were renamed national forests in 1908 , Boise National Forest was split from Sawtooth National Forest into an independent national forest . On April 1 , 1944 the entirety of what was then Payette National Forest was transferred to Boise National Forest , and simultaneously <unk> and Idaho national forests were combined to reestablish the present @-@ day Payette National Forest , which is to the north of Boise National Forest . In 1933 the Boise Basin Experimental Forest was created on 8 @,@ 740 acres ( 35 @.@ 4 km2 ) of the forest near Idaho City to study the management of ponderosa pine . The Lucky Peak Nursery was established in 1959 to produce trees for planting on burned or logged lands on the national forests of the <unk> region . 
 After the creation of the Civilian Conservation Corps ( <unk> ) in 1933 , nine camps and eight <unk> were set up in Boise National Forest , but the number of camps was reduced from 1934 until the program was closed in 1942 . Work conducted by the <unk> included fire suppression , fish habitat improvement , and construction of guard houses , fire lookouts , campgrounds , roads , and trails , among other facilities . 
 
 = = Management = = 
 
 Boise National Forest is managed by the U.S. Forest Service , an agency within the Department of Agriculture , as five units called ranger districts . The ranger districts are Cascade ( 400 @,@ 000 acres or 1 @,@ 600 square kilometers ) , Emmett ( 350 @,@ 000 acres or 1 @,@ 400 square kilometers ) , Idaho City ( 400 @,@ 000 acres ) , Lowman ( 400 @,@ 000 acres ) , and Mountain Home ( 650 @,@ 000 acres or 2 @,@ 600 square kilometers ) ; each has an office in their respective cities and is managed by a district ranger , while forest headquarters are located in the city of Boise . Congress proclaimed 2 @,@ 648 @,@ 273 acres ( 10 @,@ <unk> @.@ 18 km2 ) of Idaho part of Boise National Forest , but the forest manages only 2 @,@ 203 @,@ 703 acres ( 8 @,@ 918 @.@ 07 km2 ) . The proclaimed boundary is set and can only be changed by Congress whereas the administered boundary can be shifted among adjacent national forests without congressional approval . For management ( and from the visitor 's perspective ) the forest 's boundaries are its administered area . 
 
 = = Geography and geology = = 
 
 <unk> in the forest range from 2 @,@ 800 feet ( 850 m ) in the North Fork Payette River Canyon to 9 @,@ 730 feet ( 2 @,@ 970 m ) at the top of Steel Mountain , a gain of 6 @,@ 930 feet ( 2 @,@ 110 m ) . The forest contains several <unk> of the Rocky Mountains , including the Boise , Salmon River , and West mountain ranges . Much of the forest is <unk> by the Idaho Batholith , and the forest is dominated by <unk> rock , but <unk> of basalt can be found to the west and other volcanic rocks to the south . 
 North of the South Fork Payette River and east of the North Fork Payette River , the forest is part of the Salmon River Mountains , which extend north and east outside the forest 's boundaries . The South Fork Salmon River Range and the North Fork Range are <unk> of the Salmon River Mountains within Boise National Forest . The Boise Mountains cover much of the southern portion of the forest and contain the forest 's highest point , Steel Mountain , but the range 's highest point , Two Point Mountain , lies outside of the forest 's boundary . The Trinity Mountains are a <unk> in southeastern part of the Boise Mountains that reach their peak at 9 @,@ 451 feet ( 2 @,@ 881 m ) on Trinity Mountain . The westernmost portion of the forest south and west of Lake Cascade are part of the West Mountains , which reach their highest point at 8 @,@ 320 feet ( 2 @,@ 540 m ) on <unk> Mountain . The <unk> Mountains are a smaller range on the forest 's southern border that run northwest to southeast . 
 
 = = = Waterways = = = 
 
 There are an estimated 9 @,@ 600 miles ( 15 @,@ 400 km ) of perennial and intermittent streams and 15 @,@ 400 acres ( 62 km2 ) of lakes and reservoirs in the forest . The Forest Service provides access to and recreation opportunities at the seven reservoirs it borders , although it does not own or manage them . There are numerous natural lakes in the forest , most of which are <unk> created by alpine glaciers during the Pleistocene . The largest , Warm Lake , is 26 miles ( 42 km ) east of Cascade in Valley County ; many of the smaller lakes are in the Trinity and West mountains . Annual water yield on the forest is estimated at 4 @.@ 1 million acre @-@ feet ( 5 @.@ 1 × 109 m3 ) . The southern portion of the forest is drained by the Boise River , the central and western portions by the Payette River , northeastern portion by the Salmon River , and far western portions of the Emmett Ranger District by the <unk> River . All four rivers are tributaries of the Snake River , which itself is a tributary of the Columbia River in the Pacific basin . 
 
 = = Climate = = 
 
 Daily high temperatures range from 9 to 29 ° F ( − 13 to − 2 ° C ) in winter to 80 to 90 ° F ( 27 to 32 ° C ) in summer , while lower elevations can experience conditions over 100 ° F ( 38 ° C ) . Idaho 's mountain ranges can block Arctic air in the winter , but when cold air masses do enter the area , they sometimes <unk> in the Snake and Salmon river valleys , causing very cold temperatures to persist . Summer and fall are generally dry , while intense short @-@ duration thunderstorms can occur in late spring and early summer as atmospheric moisture interacts with warm temperatures and steep topography via <unk> lifting . During winter , warm , moist air from the Pacific Ocean often brings rain at lower elevations in addition to snowfall throughout the forest . The influence of these Pacific maritime air masses increases as latitude increases in the forest . Average annual snowfall ranges from 55 inches ( 140 cm ) in drier areas and at lower elevations to 70 inches ( 180 cm ) in wetter locations and higher elevations . The growing season within the forest ranges from over 150 days in lower elevations to less than 30 days in alpine areas . 
 
 = = Natural resources = = 
 
 Boise National Forest is within the Idaho Batholith ecoregion , which is a level III ecoregion in the larger level I Northwestern Forested Mountains . In addition to species listed or proposed for listing as threatened or endangered under the Endangered Species Act , the Forest Service maintains an independent listing of sensitive species for which it is directed to " develop and implement management practices to ensure that species do not become threatened or endangered because of Forest Service actions . " As of February 2013 there were 27 species in Boise National Forest listed as sensitive species : 6 mammals , 1 amphibian , 1 fish , 13 birds , and 6 plants . 
 
 = = = Flora = = = 
 
 An estimated 76 percent of Boise National Forest is forest , which according to the Forest Service is considered land capable of supporting trees on at least 50 percent of its area . The forests are primarily coniferous <unk> , dominated by Douglas fir and ponderosa and lodgepole pines at lower elevations and Engelmann spruce , subalpine fir , and <unk> pine at higher elevations . Grand fir and western <unk> ( a coniferous deciduous tree ) grow in the northern part of the forest where there are moister conditions . <unk> <unk> , a broadleaf deciduous tree , grows both in stands among conifers and in monotypic stands throughout the forest at elevations above 5 @,@ 000 feet ( 1 @,@ 500 m ) . Non @-@ forested areas occupy 23 percent of the forest , primarily on south @-@ facing slopes , lower elevations in the forest 's southern latitudes , or high @-@ elevation areas and are dominated by grasses , forbs , or shrubs . 
 <unk> 's <unk> is a plant species endemic to central Idaho , including parts of Boise National Forest , being found nowhere else in the world . Only about two dozen populations of the plant are known to exist , and three @-@ quarters of these are in Boise National Forest . It is usually found at elevations ranging from 5 @,@ 000 feet ( 1 @,@ 500 m ) to 9 @,@ 500 feet ( 2 @,@ 900 m ) above sea level and produces white flowers shortly after snowmelt . 
 Boise National Forest is directed by the U.S. Forest Service to " control the establishment , spread , or invasion of non @-@ indigenous plant species in otherwise healthy native <unk> ecosystems . " The forest 's plan addresses the need to control invasive plants , and management efforts include chemical , mechanical , and biological control methods . Invasive plants that are of particular concern in Boise National Forest include spotted <unk> , yellow star @-@ <unk> , rush <unk> , and leafy <unk> , among others . 
 
 = = = <unk> communities = = = 
 
 The <unk> , <unk> forested areas occur on south @-@ facing slopes from 3 @,@ 000 feet ( 910 m ) to 6 @,@ 500 feet ( 2 @,@ 000 m ) . Due to the occurrence of frequent non @-@ lethal fires , ponderosa pine dominates these forests alongside Douglas fir . The understory consists of bluebunch wheatgrass , Idaho <unk> , mountain snowberry , and <unk> in drier areas and elk <unk> , <unk> , white <unk> , <unk> <unk> , and common snowberry at higher elevations . 
 In cool , moist areas ranging from 4 @,@ 800 feet ( 1 @,@ 500 m ) to 6 @,@ 800 feet ( 2 @,@ 100 m ) , Douglas fir is predominant . <unk> pine and <unk> <unk> may be found alongside Douglas fir in cooler areas , both moist and dry , but particularly where <unk> pockets form . <unk> in this forest type are dominated by mountain maple , mountain ash , and blue <unk> in moister areas and white <unk> , common snowberry , elk <unk> , and <unk> in drier areas . Between 3 @,@ 400 feet ( 1 @,@ 000 m ) and 6 @,@ 500 feet ( 2 @,@ 000 m ) in the moist northern parts of the forest , grand fir is predominant and western <unk> is one of the first trees to become established during ecological succession following disturbances , whereas <unk> consist of mountain maple , mountain ash , blue <unk> , and <unk> <unk> . <unk> fir dominates from 4 @,@ 800 feet ( 1 @,@ 500 m ) to 7 @,@ 500 feet ( 2 @,@ 300 m ) along with mountain maple , <unk> , <unk> 's <unk> , <unk> alder , <unk> , Utah <unk> , and mountain ash . 
 <unk> pine dominates in cold , dry areas from 5 @,@ 200 feet ( 1 @,@ 600 m ) to 9 @,@ 200 feet ( 2 @,@ 800 m ) . The understory in lodgepole pine forests can be sparse but includes grasses , forbs , <unk> , and grouse <unk> , although fires in these forests are typically lethal to trees and <unk> alike . At the highest elevations , forests consist of subalpine fir alongside <unk> pine and Engelmann spruce . Grasses and forbs tolerant to freezing throughout the growing season occupy the understory . 
 <unk> typically dominates drier , non @-@ forested areas at lower elevations . Species that commonly occur with sagebrush include <unk> <unk> , wild onion , milk <unk> , bluebunch wheatgrass , <unk> , gray <unk> , green <unk> , and others . In riparian areas below 5 @,@ 500 feet ( 1 @,@ 700 m ) , trees such as black cottonwood , <unk> cottonwood , <unk> alder , water birch , and mountain maple grow with shrubs including <unk> and willows . <unk> areas in largely <unk> habitats such as sagebrush steppe primarily consist of willows along with <unk> alder , <unk> , mountain maple , shrubby <unk> , <unk> , <unk> , and grasses . 
 
 = = = Fauna = = = 
 
 <unk> in Boise National Forest support nearly 300 terrestrial <unk> species and 28 fish species . The most common large animals are mule deer and elk , but other mammals present include moose , black bears , <unk> , mountain lions , coyote , bobcat , yellow @-@ bellied <unk> , beaver , and gray wolves . 
 Gray wolves are top predators that were reintroduced amidst controversy to central Idaho in the mid @-@ 1990s to restore ecosystem stability . The wolves have since expanded their range and established packs in most of Boise National Forest . Wolves and mountain lions are the forest 's top large mammal predators and have no predators of their own except humans . Most of the forest 's native mammal species are present in the forest , with the exception of grizzly bears , which have become locally extinct , and plans for their reintroduction to central Idaho have been proposed since the 1990s but have not progressed . 
 Of the 28 fish species present in the forest , 11 are not native and have been introduced by humans . Rainbow trout , <unk> salmon , <unk> <unk> trout , bull trout , and mountain <unk> are all native to some of the forest 's waterways , while brook trout are a common invasive species that compete with the forest 's <unk> . The forest 's management indicator species is bull trout because they are sensitive to habitat changes and depend on specific habitat conditions . <unk> salmon are native to the Salmon River watershed in the northern part of the forest , but dam construction on the Columbia and Snake rivers has hampered the migration of this <unk> fish and caused its population to collapse . Warm Lake supports the forest 's only native population of Kokanee salmon , the resident ( non @-@ migratory ) form of sockeye salmon . However , due to introductions by humans , Anderson Ranch , <unk> , Lucky Peak , and Deadwood reservoirs now support populations of Kokanee salmon . To provide additional recreational fishing opportunities , the Idaho Department of Fish and Game stocks several of the forest 's waterways with rainbow trout , while reservoirs are also stocked with Kokanee or <unk> salmon and Lake Cascade is stocked with <unk> salmon and <unk> , the <unk> form of rainbow trout . 
 Over 270 bird species have been observed in central Idaho , including 36 accidental species – those that are not normally found in the region but have been observed on at least one occasion . Golden eagles and greater sage @-@ grouse can be found over sagebrush steppe , whereas bald eagles can be seen along rivers . The Forest Service has listed northern <unk> , <unk> owls , and white @-@ headed woodpeckers as a sensitive species in the forest . 
 The few amphibians present in the forest include the Rocky Mountain tailed frog , long @-@ toed <unk> , and Columbia spotted frog , which has been listed as a sensitive species . Common snakes include <unk> , <unk> snakes , and rubber <unk> . 
 
 = = = Fire ecology = = = 
 
 Boise National Forest 's 2010 forest plan recognizes that fire and other disturbances play important roles in maintaining the character and function of ecosystems . However , previous management strategies ( as recently as the 1990 forest plan ) treated fire as an undesirable process , and the <unk> Act of 1897 explicitly stated that forests were to be protected from destruction by fire . In historic conditions fires naturally occurred on the landscape ; the suppression of fires allowed dead trees to accumulate in excess of historic levels and land cover types to change , such as a shift to higher shrub and tree densities . An estimated 14 percent of the land in Boise National Forest has been affected by fires since the early 1990s , and about 10 percent of the land capable of timber production was burned so severely that land cover shifted from forest to grass and <unk> ( as of 2010 ) . 
 Between 2004 and 2013 an average of 74 @,@ 325 acres ( 300 @.@ 78 km2 ) were burned by fires per year with a maximum of 346 @,@ 500 acres ( 1 @,@ 402 km2 ) in 2007 and a minimum of 152 acres ( 0 @.@ 62 km2 ) in 2008 . For example , in 2012 there were 26 fires started by people and 109 started by lightning , which together burned a total of 152 @,@ 000 acres ( 620 km2 ) . The Trinity Ridge Fire alone burned 146 @,@ 800 acres ( <unk> km2 ) over two months , although it was not confined to Boise National Forest lands . 
 The revised 2010 forest plan recognized the need to develop plans to manage <unk> at the <unk> – urban interface , use prescribed fire as a tool to manage ecosystem health , and meet air quality requirements set by the Clean Air Act . The forest operates a fire management plan under federal fire policy that gives fire personnel direction for responding to <unk> <unk> . Occasionally , area closures and restrictions on use , such as prohibition of <unk> , are implemented to aid in <unk> prevention . Following severe fires , area closures may be put in place to protect the public from risks such as falling trees and landslides . <unk> fire management strategies include prescribed burns and mechanical reduction of fuel levels . For instance , in 2014 Boise National Forest planned to conduct 7 @,@ <unk> acres ( 32 @.@ 05 km2 ) of prescribed burns and 155 acres ( 0 @.@ 63 km2 ) of mechanical treatment . The forest seasonally maintains staff at seven fire lookout towers , while six others remain <unk> . 
 
 = = Recreation = = 
 
 There are over 70 campgrounds in Boise National Forest and groups of more developed recreation facilities at the Trinity Mountains , Warm Lake , and Deadwood and Sage Hen reservoirs . As in most national forests , the majority of the land in Boise National Forest is open to dispersed camping ( outside of developed campgrounds ) . One of the forest 's fire lookouts , Deadwood <unk> , is now available as a cabin for the public to rent , among other sites . <unk> are allowed on forest roads and on more than 1 @,@ 300 miles ( 2 @,@ 100 km ) of multiple @-@ use trails , whereas over 1 @,@ 200 miles ( 1 @,@ 900 km ) of trails are open to <unk> recreation . The <unk> Mountains Off @-@ Highway Vehicle Trail System contains 150 miles ( 240 km ) of motorcycle and ATV trails on 60 @,@ 000 acres ( 24 @,@ 000 ha ) of land that is generally open from April through November . The forest 's Trinity Mountain Recreation Area includes the highest <unk> ( 4 @-@ wheel drive recommended ) road in Idaho , which <unk> to the Trinity Mountain <unk> at an elevation of over 9 @,@ 400 feet ( 2 @,@ 900 m ) . In 2013 revenues from recreation and special use fees amounted to $ 454 @,@ 635 , while expenses totaled US $ 352 @,@ 550 ; the difference is allocated to the following season 's startup costs . 
 
 = = = Waterways = = = 
 
 Rivers in Boise National Forest offer the opportunity for rafting and <unk> through rapids up to class four , with the most difficult sections on the South Fork and main stems of the Payette River . Numerous developed boat launch sites provide access to rivers for whitewater enthusiasts , and <unk> Falls is the primary launching site for visitors to the Middle Fork of the Salmon River and Frank Church River of No Return Wilderness . <unk> boating is permitted on Anderson Ranch Reservoir , Deadwood Reservoir , and Warm Lake . 
 
 = = = Winter activities = = = 
 
 During winter , visitors to the forest can participate in activities including <unk> , <unk> , and <unk> and cross @-@ country skiing . The <unk> Basin <unk> area is located within the forest north of Boise and has 7 <unk> and 53 runs on 2 @,@ 600 acres ( 11 km2 ) of <unk> terrain . There are 137 miles ( 220 km ) of <unk> <unk> trails in the Garden Valley system in the Emmett Ranger District and several Mongolian @-@ style <unk> available for rental in winter . 
 
 = = = Scenic roads = = = 
 
 Boise National Forest is home to three of Idaho 's scenic <unk> , all of which are paved highways accessible to <unk> vehicles . The Payette River Scenic Byway is an 80 @-@ mile ( 130 km ) route between Eagle and McCall on Idaho State Highway 55 . The route follows the Payette River between McCall and Horseshoe Bend , but the majority of the highway does not pass through Boise National Forest ; only a small portion north of Horseshoe Bend is in the Emmett Ranger District . Over half of the 35 @-@ mile ( 56 km ) Wildlife Canyon Scenic Byway , which travels between highway 55 and Lowman , passes through the forest , parallels the South Fork of the Payette River , and is signed as the Banks @-@ Lowman Road . The Ponderosa Pine Scenic Byway is a 130 @-@ mile ( 210 km ) road between Stanley and Boise following Idaho State Highway 21 . This route passes over <unk> Reservoir and through Idaho City and Lowman , where it connects with the Wildlife Canyon Byway . North and east of Lowman the <unk> partially follows the South Fork of the Payette River before ascending to the 7 @,@ <unk> @-@ foot ( 2 @,@ 145 m ) Banner Creek Summit at the forest 's boundary with Salmon @-@ <unk> National Forest . 
 
 