The Colorado Pinyon, Two-needle Pinyon or Pion Pine (Pinus edulis) is a pine in the pinyon pine group whose ancestor was a member of the Madro-Tertiary Flora (a group of drought resistant trees) and is native to the United States. The range is in Colorado, southern Wyoming, eastern and central Utah, northern Arizona, New Mexico, and the Guadalupe Mountains in westernmost Texas. It occurs at moderate altitudes from 1600-2400 meter, rarely as low as 1400 meter and as high as 3000 meter. It is widespread and often abundant in this region, forming extensive open woodlands, usually mixed with junipers. The Colorado pinyon (pion) grows as the dominant species on 4.8 million acres (19,000 km) in Colorado, making up 22% of the state's forests. The Colorado pinyon has cultural meaning to agriculture, as strong pion wood "plow heads" were used to break soil for crop planting at the state's earliest known agricultural settlements. There is one known example of a Colorado Pinyon growing amongst Engelmann spruce (Picea engelmannii) and limber pine (Pinus flexilis) at nearly 3,170 meters (10,400 feet) on Kendrick Peak in the Kaibab National Forest of northern Arizona.