Jefferson Peak is a mountain

summit A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topography, topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used ...

located in the

Olympic Mountains The Olympic Mountains are a mountain range on the Olympic Peninsula of the Pacific Northwest of the United States. The mountains, part of the Pacific Coast Ranges, are not especially high – Mount Olympus is the highest at ; however, the easter ...

in Mason County of

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

state. It is situated in the

Mount Skokomish Wilderness Mount Skokomish Wilderness is a designated wilderness area in the southeast portion of Olympic National Forest on the Olympic Peninsula of Washington in the United States. The wilderness area comprises administered by the U.S. Forest Service. H ...

, on land managed by Olympic National Forest. The mountain's toponym honors

Thomas Jefferson Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Fathers of the United States, Founding Father who served as the third president of the United States from 18 ...

(1743–1826), the third president of the United States.Kai Huschke (2003), ''Washington's Wilderness Areas'', Westcliffe Publishers, , page 48. The nearest higher neighbor is

line parent A peak's line parent is the closest higher peak on the highest ridge leading away from the peak's "key col". A col is the lowest point on the ridge between two summits and is roughly synonymous with pass, gap, saddle and notch. The highest col of ...

Mount Pershing, to the southwest. Precipitation

runoff Runoff, run-off or RUNOFF may refer to: * RUNOFF, the first computer text-formatting program * Runoff or run-off, another name for bleed, printing that lies beyond the edges to which a printed sheet is trimmed * Runoff or run-off, a stock market ...

drains into Jefferson Creek and the Hamma Hamma River. Topographic relief is significant as the north aspect rises over above the Hamma Hamma valley in approximately one mile.

Climbing

The

first ascent In mountaineering, a first ascent (abbreviated to FA in guide books) is the first successful, documented attainment of the top of a mountain or the first to follow a particular climbing route. First mountain ascents are notable because they en ...

of the summit was made in 1958 by Don Anderson, Bob Oram, Keith Spencer, and Robert Petersen. There are three established scrambling routes to the summit: from Goober Pond, the North Couloir, and via the East Peak. Jefferson Peak has a 250-foot-high () subpeak called "Tran Spire" () which was first climbed in 1958 by Don Anderson and Robert Petersen .

Climate

Jefferson Peak is located in the marine west coast climate zone of western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. Weather fronts originating in the Pacific Ocean travel northeast toward the Olympic Mountains. As fronts approach, they are forced upward by the peaks ( orographic lift), causing them to drop their moisture in the form of rain or snow. As a result, the Olympics experience high precipitation, especially during the winter months in the form of snowfall. Because of maritime influence, snow tends to be wet and heavy, resulting in

avalanche An avalanche is a rapid flow of snow down a slope, such as a hill or mountain. Avalanches can be set off spontaneously, by such factors as increased precipitation or snowpack weakening, or by external means such as humans, animals, and earth ...

danger. During winter months weather is usually cloudy, but due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer. The months April through August offer the most favorable weather for viewing or climbing this mountain.

Geology

The Olympic Mountains are composed of obducted

clastic Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks ...

wedge material and oceanic crust, primarily

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

, turbidite, and

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic oceanic crust. The mountains were sculpted during the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

era by erosion and glaciers advancing and retreating multiple times.

Gallery

File:Jefferson mtn.jpg, Jefferson Peak centered.
(Mount Bretherton and Mount Constance to left, The Brothers to right) File:Ferry on Puget Sound.jpg, Ferry on Puget Sound. Left to right: Mt. Pershing, Jefferson Peak, Mt. Cruiser, Mt. Skokomish, Mt. Stone File:Olympics above low clouds.jpg, Left to rightː Mt. Ellinor, Mt. Washington, Mt. Pershing, Jefferson Peak.
View from Seattle. File:Olympic range mtn.jpg, Jefferson Peak

References

External links

* Weather forecast
Jefferson Peak

Mount Skokomish Wilderness
U.S. Forest Service {{Geographic Location 2 , Center = Jefferson Peak , North = Mount Bretherton , Northeast = The Brothers , East = Jefferson Lake , Southeast = Jefferson Creek , South =

Mount Washington Mount Washington is the highest peak in the Northeastern United States at and the most topographically prominent mountain east of the Mississippi River. The mountain is notorious for its erratic weather. On the afternoon of April 12, 1934, ...

, Southwest = Mount Pershing , West = Mount Cruiser , Northwest =

Mount Skokomish Mount Skokomish is a 6,434 ft (1,961 meter) mountain summit located in the Olympic Mountains, in Mason County of Washington state. It is situated on the shared boundary of Olympic National Park with Mount Skokomish Wilderness, and is t ...