Mount Adams stands 37 miles (60 km) east of Mount St. Helens and about 50 miles (80 km) south of Mount Rainier. It is 30 miles (48 km) north of the Columbia River and 55 miles (89 km) north of Mount Hood in Oregon. The nearest major cities are Yakima, 50 miles (80 km) to the northeast, and the Portland metropolitan area, 60 miles (97 km) to the southwest. Between half and two thirds of Adams is within the Mount Adams Wilderness of the Gifford Pinchot National Forest. The remaining area is within the Mount Adams Recreation Area of the Yakama Indian Reservation.

Although Mount Adams has not erupted in more than 1,000 years, it is not considered extinct. Too, it is the second-highest mountain in Washington, after Mount Rainier and the third highest in the Cascade Range. Because of the way that it has developed, it is the largest stratovolcano in Washington state and second-largest in the Cascades, behind only Mount Shasta. Its large size is reflected in its 18 mille diameter base, which has a prominent north-south trending axis.

This mountain, named for President John Adams is a member of the Cascade Volcanic Arc and is one of the arc′s largest volcanoes. Mount Adams is located in a remote wilderness and is found further east than any other Washington volcano. The Mount Adams Wilderness consists of the upper and western part of the volcano′s cone. The eastern side of the mountain is designated as part of the territory of the Yakama Nation.

The volcano which is Mount Adams has an asymmetrical and broad body which rises 1.5 miles (2.4 kilometers) above the Cascade Crest. Its nearly flat summit was formed as a result of cone building eruptions from several separated vents.

Mount Adams is the source of the headwaters for two major river, the Lewis River and White Salmon River. Too, the many streams that emanate from the glaciers and from springs at its base flow into two more major river systems, the Cispus River and the Klickitat River. The streams on the north and west portions of Adams feed the Cispus River, which joins the Cowlitz River near Riffe Lake, and the Lewis River.

In terms of access to stratovolcanoes in Washington, Mount Adams is the second-most isolated volcano with Glacier Peak being the most isolated. The mountain′s large size and distance from major cities, and the tendency of some people to forget or ignore Mount Adams, has led some people to call this volcano "The Forgotten Giant of Washington"

The Pacific Crest Trail traverses the western flank of the mountain.

On a clear day from the summit, other visible volcanoes in the Cascade Range include: Mount Rainier, Mount Baker, and Glacier Peak to the north, as well as Mount St. Helens to the west, all in Washington; and Mount Hood, Mount Jefferson, and the Three Sisters, all to the south in Oregon.

Only two major highways pass close to it. Highway 12 passes about 25 miles (40 km) to the north of Adams through the Cascades. Highway 141 comes within 13 miles (21 km) of Adams as it follows the White Salmon River valley up from the Columbia River to the small town of Trout Lake. From either highway, travelers have to use Forest Service roads to get closer to the mountain. The main access roads, FR 23, FR 82, FR 80, and FR 21, are paved for part of their length.

Almost all other roads are gravel or dirt, with varying degrees of maintenance. Access to the Mount Adams Recreation Area is by way of FR 82, which becomes BIA 285 at the Yakama reservation boundary. BIA 285 is known to be extremely rough and often suitable only for trucks or high-clearance vehicles.

Two small towns, Glenwood and Trout Lake, are located in valleys within 15 miles (24 km) of the summit, Glenwood on the southeast quarter and Trout Lake on the southwest quarter.