The andesitic-dacitic volcano was built by several overlapping cones. Eruptions from Mount Adams began about 520 ka, although scattered basaltic eruptions from the surrounding volcanic field began by about 940 ka. Mount Adams is the center of a 200 km3 volcanic field.

The volcano is 3,742 m (12,276 ft) in elevation and towers about 3 km (9,800 ft) above the surrounding lowlands. Mount Adams, known by some Native American tribes as Pahto or Klickitat, is a potentially active stratovolcano in the Cascade Range.Although Adams has not erupted in more than 1,000 years, it is not considered extinct. When it did erupt they were small, infrequent and effusive. The volcanic field includes the 200 km3 Mount Adams complex andesitic-dacitic stratovolcano, elongated along a NNW-SSE line, and more than 60 flank vents. When it did erupt they were small, infrequent and effusive. By about 460 ka the eruption focus shifted to a position beneath the modern volcano, and subsequent eruptions constructed an encircling apron of lava flows that extend … Mt Adams hasn't erupted for 1,000 years. Although it has not had a major eruption in 1,400 years, it is not considered extinct. By about 460 ka the eruption focus shifted to a position beneath the modern volcano, and subsequent eruptions constructed an encircling apron of lava flows that extend … Eruption Dates: 950 A.D. 200 A.D. 300 B.C. Mount Adams in Washington state is a stratovolcano in the Cascade Mountains about 31 miles from Mount St Helen’s which erupted in 1980. Shasta. Mount Adams is a potentially active volcano located 50 km east of Mount St. Helens, and is the second highest peak in Washington State.

The upper flanks of Mount Adams consist of glaciers, jagged ridges and cliffs, glacial moraines, and alpine meadows, but below an elevation of about 2,000 m (6,500 ft) most of the landscape is densely forested.

Thermal anomalies and gas emissions at the summit indicate that Mount Adams is still active. Mount Adams is a potentially active volcano located 50 km east of Mount St. Helens, and is the second highest peak in Washington State. Mt Adams stratovolcano 50 km east of Mt St Helens volcano is the by volume second largest volcano of the Cascades Range, after Mt.

The 2190 eruption of Mt Adams was a highly destructive, very unexpectedly violent eruption that began at 1345 PDT on February 18, 2190. The last eruption is estimated to have occurred in 550 BC give or take a thousand years. Early edifice building was focused 5 km (3 mi) southeast of the modern summit. The summit icecap and ten glaciers only cover about 2.5% of volcano's surface area, but during the last glacial maximum as much as 80% of Mount Adams was under ice. Ice-capped Mount Adams sits astride the Cascade Range crest 50 km (30 mi) north of the Columbia River and 60 km (37 mi) east of Mount St. Helens. Between 15 and 14 ka, two cinder cones fed lava flows on upper and lower flanks of Mount Adams, and a short fissure eruption occurred within the surrounding field.