Mount Hood – The Highest Mountain in Oregon

Mount Hood is the highest mountain in Oregon and the fourth highest in the Cascade Range. It is located about 50 miles (80 km) east of the Portland metropolitan area. The mountain contributes a major supply of water, scenic, and recreational resources, sustaining the agricultural and tourist sectors of the surrounding communities.

Mount Hood's height estimates have fluctuated throughout its history, and actual changes in elevation due to mild seismic activity are not the only reason for that.

In the past, the height estimates varied considerably—from 10,000 feet (3,000 m) estimated by early explorers to 19,400 feet (5,900 m) estimated by Mr. Belden, who claimed to have climbed the mountain. At some point, Mt Hood was even considered the highest peak in North America.

Modern technology allowed to mitigate the range of estimates and to reduce the list of possible heights to three - 11,240 feet (3,426 m), 11,239 feet (3,426 m), and 11,249 feet (3,429 m).

Mt Hood's peak is covered by 12 named glaciers and permanent snowfields with the total area of around 5 square miles (13.5 square km). The summer meltdown of glaciers and seasonal snowpacks provides irrigation to the Hood River Valley well-known for its fruit orchards.

Oregon’s volcano is most likely to erupt within the next 30 years, with a probability between 3% and 7%. Like the infamous Vesuvius (responsible for the destruction of ancient Pompeii), Mount Hood is a stratovolcano built by multiple layers of hardened lava, tephra, pumice, and volcanic ash.

Mount Hood is more than 500,000 years old. The volcano has grown in fits and starts, with periods of frequent eruptions followed by dormant periods. The last major eruption happened in the 1790s. Crater Rock, a 550-foot lava dome on the mountain’s southern side, serves as a reminder of those events.

In 1806, explorers Meriwether Lewis and William Clark came across a wide, shallow river with a bed “formed entirely of quicksand.” They named it Quicksand River, which later became Sandy River. Mount Hood is why the contemporary narrow and relatively deep Sandy River is so different from the description provided by Lewis and Clark. Massive amounts of rock and sand resulting from the 1790s eruption ended up in the Sandy River and were yet to be removed by the stream at the time of the Lewis and Clark expedition.

Minor explosive activities were reported in 1865, but since then, the mountain has remained relatively quiet. The US Geological Survey (USGS) considers the volcano “potentially active” and monitors it closely. Scientists expect the next eruption to take the form of small explosions, growth, and the collapse of lava domes, generating pyroclastic flows, ash clouds, and lahars. A significant eruption of Mount Hood would displace several thousand residents and cause billion-dollar damage to property.