Pinus ponderosa, commonly known as the ponderosa pine, bull pine, blackjack pine, or western yellow-pine, is a very large pine tree species of variable habitat native to the western United States and Canada.
 It is the most widely distributed pine species in North America.
Abert's squirrel (or tassel-eared squirrel) ("Sciurus aberti") is a tree squirrel in the genus "Sciurus" endemic to the Rocky Mountains from United States to Mexico, with concentrations found in Arizona, the Grand Canyon, New Mexico, and southwestern Colorado.
 It is closely associated with, and largely confined to, cool dry ponderosa pine forests.
 It is named in honour of the American naturalist John James Abert and nine subspecies are recognised.
 It is recognisable by its tufted ears, gray color, pale underparts and rufous patch on the lower back.
 When available, it feeds on the seeds and cones of the Mexican pinyon and the ponderosa pine, but will also take fungi, buds, bark and carrion.
 Breeding normally takes place in summer, with a spherical nest being built high in the canopy.
 This is a common species with a wide range and the International Union for Conservation of Nature has rated its conservation status as being of "least concern".
The Eastern Cascades Slopes and Foothills ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Oregon, Washington, and California.
 In the rain shadow of the Cascade Range, the eastern side of the mountains experiences greater temperature extremes and receives less precipitation than the west side.
 Open forests of ponderosa pine and some lodgepole pine distinguish this region from the Cascades ecoregion, where hemlock and fir forests are more common, and from the lower, drier ecoregions to the east, where shrubs and grasslands are predominant.
 The vegetation is adapted to the prevailing dry, continental climate and frequent wildfire.
 Volcanic cones and buttes are common in much of the region.
The maritime coast range ponderosa pine forests are rare temperate forest assemblages associated with a limited range portion of the Santa Cruz Mountains of northern California.
 There are only three known small forests of this type, all situated in Santa Cruz County, California.
 The dominant tree species is the ponderosa pine.
The Ochoco Mountains are a mountain range in central Oregon in the United States, located at the western end of the Blue Mountains.
 They were formed when Permian, Triassic, and Jurassic rocks were slowly uplifted by volcanic eruptions to form the Clarno Formation.
 Today, the highest point in the range is Lookout Mountain.
 The dominant vegetation on the west side of the range is old-growth ponderosa pine; on the east side, western juniper is common.
 The western area of the mountains is administered by the Ochoco National Forest, while the southeastern section is part of the Malheur National Forest.
 The Ochoco Mountains are used for hiking, camping, bird watching, rockhounding, and hunting, as well as cross-country skiing in the winter.
The Rocky Mountain ponderosa pine forest is a forest plant community at an elevation of 2100 - in the Rocky Mountains, in the U.S. state of Colorado.
 It is an important temperate coniferous forest ecoregion, including some endemic wildlife and grass species that are only found in this ponderosa pine ("Pinus ponderosa") habitat.
Grosmannia clavigera is a species of sac fungus that causes blue stain in wood.
 It spreads to lodgepole pine, ponderosa pine, Douglas-fir, and whitebark pine trees from the body and a special structure in the heads of mountain pine beetles.
 The blue stain fungus has evolved a relationship with mountain pine beetles that allow them to travel from tree to tree on a special structure in the beetle’s heads and stops the tree from producing resin to pitch out or kill the beetle, encouraging the pine beetle infestation occurring all along the Rocky Mountains from Mexico into Canada.
 The beetles are able to mine and lay eggs while avoiding the tree’s defenses.
 The 33 Mb genome of this fungus was sequenced in 2009.
Pinus arizonica, commonly known as the Arizona pine, is a medium-sized pine in northern Mexico, southeast Arizona, southwest New Mexico, and western Texas in the United States.
 It is a tree growing to 25–35 m tall, with a trunk diameter of up 1.2 m .
 The needles are in bundles of 3, 4, or 5, with 5-needle fascicles being the most prevalent.
 This variability may be a sign of hybridization with the closely related ponderosa pine ("Pinus ponderosa").
 The cones are single, paired, or in whorls of three, and 5–11 cm long.
The Big Tree (also known as the Trout Lake Big Tree) was a massive Ponderosa pine tree in old growth pine and fir forest in southern Washington state, at the southern base of Mount Adams.
 It is managed by the Mount Adams Ranger District of the Gifford Pinchot National Forest.
 The tree is 202 ft tall with a diameter of 7 ft , and was one of the largest known ponderosa pine trees in the world.
 It had been stressed by attacks from mountain pine beetles and its death in 2015 was confirmed the following year.
Lomatium ochocense is a rare species of flowering plant in the carrot family known by the common name Ochoco lomatium.
 It is endemic to Oregon, where it is limited to the Ochoco Mountains of Crook County.

Question: What is the formal name of the tree that is the dominant vegetation on the west side of the Ochoco Mountains, commonly known as the ponderosa pine?
Answer: ponderosa pine