Mount Bonaparte is a mountain located in the Okanagan Highlands of Northeastern central Washington, United States. The mountain is both the highest mountain in the Washington section of the Okanagan Highlands and the third-highest Washington peak east of the Okanogan River. Located in Okanogan County between the unincorporated communities of Havillah and Wauconda the closest city is Tonasket.
The summit of Mount Bonaparte has been a fire lookout location since as early as 1904 when a solitary peak walker would camp at the summit under a tent. The first permanent Mount Bonaparte Lookout, a ground cabin with tower structure built above the roof was constructed in 1914. The tower was used through 1929 when a new lookout was funded. Additionally during the 1929 season, a cistern was carved into the summit granite which could hold enough snow and rain water to support the lookout needs over the summer months. Built in 1930, the taller lookout structure had a lookout cabin and residence on top of a wooden tower. This tower served the fire watch needs until the very early 1960s, at which time it was deconstructed. The final tower was topped with a cabin which served though 2024 and was built from helicoptered in supplies. In 2025 manning of the tower was turned over to volunteers.
This mountain can be accessed by three trails with Bonaparte Trail #306, a 5.5 mile ATV trail on the north side of the mountain leading up to the summit. Crossing over the southern slope is the Pacific Northwest Trail, which overlaps several other trails along the route and passes close to several historical cabins present on the mountain. Views from the summit reach as far as Canada, the North Cascades, the Colville Reservation, and Mount Rainier. In the winter several different Sno-Parks are maintained for snowmobile, cross-country skiing, and snowshoeing use.
Geography and geology Geography At , Mount Bonaparte is the highest mountain in the Washington section of the Okanagan Highlands and one of the highest peaks east of the Okanogan River. It rises between the unincorporated communities of Havillah and Wauconda, while the closest cities are Tonasket to the southwest and Republic to the southeast. Early reports of the elevation were often given as , with modern surveys adjusting the elevation downwards by over . The highlands in Washington are a conglomeration of mountains spanning at the widest and south from the Canadian border. Mount Boneparte is slightly shorter than Baldy Mountain, , in southern British Columbia. Mount Bonaparte has a high prominence of , the 31st highest in Washington, and 320th in the contiguous United States. It also has a high isolation of between it and its closest high neighbor, Baldy Mountain, resulting in it occasionally being considered a monadnock. By 1900 a location United States Geological Survey marker had been placed at Mount Bonapartes foot. According to the account by R. U. Goode, the marker was embedded in a rock face of the mountain foot near the end of the trail following Bonaparte Creek up from the Republic-Tonasket Road.
Geology The origin of the Okanogan highlands and Mount Bonaparte is tied to the complex history of island arc and exotic terrain emplacement along the North American Plates western edge during subduction of the Farallon Plate. The Farallon plate is suggested to have undergone a period of flat slab subduction wherein instead of curving downwards into the mantle close to the subduction point, the plate stayed close under the overriding North America Plate pushing up the Quesnellia terraine which had first accreted in the Jurassic. This resulted in the raising of a plateau region over the area possibly as much as higher than present average elevation. In the latest Cretaceous to early Paleocene, starting around the Farrallon plate started a 12 million year long slab rollback event in which it pulled down and away from Quesnellia melting the basement areas of the Quesnellian terrain. The melting occurred from roughly after which the magma pools were rapidly exposed by crustal extension and erosion from . The Challis volcanic episode around was the primary result of the rollback, with volcanic centers forming to the east of the Okanogan Highlands along the Republic Graben and the highlands themselves subjected to an estimated of lateral extension, dropping the highlands elevation down to near modern heights and helping expose the Okanagan Dome with its magma pools as plutons.
During the last ice age successive waves of the Fraser glaciation engulfed the entire region under the Cordilleran ice sheet which heavily shaped much of the regional topography. At least five glacial advance and retreat cycles started around 19,000 years before present before starting the final waning at 11,000 ybp. The mountain topography was created by glacial advance, retreat, stagnation, and retreat again. Glacial debris settled into the previously narrow and deep valley structures, formed by the gneiss domes, filling the floor to its modern contours. Glacial erratics are present along the valley floor, and the valley bottom is dominated by glacial debris and cobble deposits forming terraces and pitted outwash-plains. Glacial kettles are scattered in the central Aeneas valley area, many now containing varying sized kettle lakes.
Mount Bonaparte is composed fully of Mount Bonaparte Pluton granodiorite and quartz monzonite which were emplaced during the Okanogan Dome core complex orogenesis, and is the center of a small granitic pluton dated to in age. Mineral reconnaissance and evaluations have not shown any economic metallic or non-metallic ore deposits in the pluton and no documented mining claims are present on Mount Bonaparte. This is notable as an exception to other plutons and pluton-gneiss contact zones of the Omineca crystalline belt in northeastern Washington and southern British Columbia which have productive gold, silver, and copper deposits.
Climate Reporting in March of 1935 by forest ranges engaged in game surveys in the region recorded a snowpack depth on the eastern slope of Mount Boanparte. Within the Köppen climate classification the area of northeastern Okanogan County has a humid continental climate (Dfb). The 30-year average temperature is , with an average yearly high of in August, and an average low of in December. The average rainfall is per year. The wettest month is June, with of precipitation, while the driest is August, with .
Ecology
The mountains ecology is mixed with alpine conditions at the peak, subalpine forests near the peak grading into mixed conifer forests on the lower slopes with lake, meadow and bog environs around the mountain base. The soils over most of the mountain are derived from glacial tills though some areas have lacustrine sourced soils. Most of the soils have a fine texture but there are mixed fine and course areas as well. The finer soils have a higher water permeability, while the course soils have a higher stability factor. In the 2009 evaluation of the Mount Bonaparte Wilderness, the area was given a Bortle scale rating as Class 2, a Typically Truly Dark Sky Site. This is the second darkest sky on the scale, with very minimal light pollution, a well developed summer milky way being visible to the naked eye, and clouds and landforms visible as black patches on the starscape.
Flora The peak area of the mountain is characterized by low alpine brush and plants with scattered whitebark pine growing from a glacially polished granite landscape. The lower slopes of Mount Bonaparte have dense lodgepole pine and mixed conifer stands, and the highest elevations transition into steep rocky terrain and then barren rock at the summit and surrounding ridge tops. The southern slope and a portion of the northern slope from around up to the subalpine transition is dominated by lodgepole pine forest, while below that is mixed conifer forests. At the subalpine transition the forest switches into mixed subalpine fir and whitebark pine stands within a subalpine plants community. whitebark pine habitat is found in around four percent of the region, but the species is noted to be vulnerable to both mountain pine beetle and white pine blister rust. Dwarf mistletoe parasitism is frequently found in the Douglas fir stands. The valley floor at the southeast base of Mount Bonaparte is occupied by blue-bunch grass - big sagebrush prairie and a fen meadow along Bonaparte Creek. Early floral reports from the area included the violets Viola renifolia and Viola selkirkii collected from the slopes in 1914 and 1916. A species of shooting star, considered a Washington State plant of concern is also known from Bonaparte, while populations of noxious weeds are also present, with Houndstongue, orange hawkweed and yellow hawkweed reported across the area.
Nonvascular plants of the mountain include liverworts such as Barbilophozia hatcheri, Barbilophozia sudetica, Lophozia ventricosa, and Ptilidium pulcherrimum. Mosses from several families are present such as Coscinodon calyptratus, Dicranum fuscescens, Dicranum tauricum, Grimmia torquata Plagiothecium denticulatum, Sanionia uncinata.
Fauna The area has a history of Mountain pine beetle infestation during the 1980s resulting in notable damage to lodgepole pine stands of the mountain. Similarly an estimated of forest had been impacted by balsam woolly adelgids attacking the fir-tree species, especially subalpine fir. Great grey owls are documented occasionally in the area based on reporting in 1986. Several of the ridges around Mount Bonaparte are known winter habitat for blue grouse populations.
Mount Bonaparte has a long history of large mammals being residents of or transitory through the region. A November 1907 report by the Forest Supervisor of the time was included a mention of some 300 wild horses roaming the area of Mount Bonaparte. The herd was reported as leery of humans and considered a detriment to the range-land use of the area. Suggestions of rounding up or culling were deemed not practical. Around of the region are considered prime white-tailed and mule deer winter habitat, a status which contributed to the 1929-1939 Bonaparte Preserve designation by Washington State.
In the 2009 assessment of the potential Mount Bonaparte Wilderness area, reviewers noted that the regional ecology is not prime habitat for several of the largest of the historic highlands predators, gray wolves, grizzly bears, or wolverines. The area does act as an important connection corridor between several larger wilderness areas that are prime habitat zones in the North Cascades and the Selkirks. The area is included in state efforts to reestablish and build up the Canadian lynx population across the highlands and Kettle River Range. The area is not consisted suitable for lynx residency or reproduction needs, but has a historical record of lynx reports. Ecologists consider the area to be a travel corridor between the Kettle River Range of Washington and the western Okanagan Highlands in southern British Columbia. Called a "steppingstone" area, individuals likely spend short amounts of time foraging or residing in the area and then move on.
Rocky Mountain bighorn sheep are found in the Mount Bonaparte area along with other sections of the Okanogan highlands, Cascades, and Selkirks. Herds in the region were classified as being the subspecies Washington bighorn sheep, Ovis canadensis californiana, based on specimens taken in the late 1800s through the early 1900s. By the 1935 the last bighorn sheep holdouts in the state had been extirpated and the species was not reintroduced into sections of its historic Washington range, including the Bonaparte Creek Mountain area, until reintroduction efforts between 1957 and 2014.
Wildlands fires