The flora and fauna on the mountain are typical of those found in northern New England, with the summit hosting fragile and endangered alpine tundra.

[7] Katahdin is part of a laccolith that formed in the Acadian orogeny when an island arc collided with eastern North America approximately 400 million years ago.

Bedrock surfaces of igneous rocks which were buried by glacial sediments and only recently exposed have well preserved striations, as in the vicinity of Ripogenus Dam.

[10] The flora includes pine, spruce, fir, hemlock, beech, maple, birch, aspen, and pincushion plant (Diapensia lapponica).

Katahdin is in Baxter State Park, which is in east central Piscataquis County, about 25 mi (40 km) northwest of Millinocket.

There is low lake country to the south and west of Katahdin, and lowlands extending east to the Atlantic and north to the Saint Lawrence River in Canada.

[11] Regardless, the summit of Katahdin offers some of the longest unbroken lines of sight in the United States, and on clear days can be seen all the way from the White Mountains of neighboring New Hampshire; a distance of 170 miles (270 km).

[citation needed] Katahdin's height and isolation earns it significant coverage in indigenous and post-colonial Maine culture and literature.

In winter, the snowcapped east and west faces of Katahdin resemble "the Kilimanjaro of New England", and it dominates the otherwise flat and endless forests of the North Maine Woods.

Katahdin is referred to 60 years after Field's climb of Agiokochuk (Mount Washington) in the writings of John Gyles, a teenage colonist who was captured near Portland, Maine, in 1689 by the Abenaki.

While in the company of Abenaki hunting parties, he traveled up and down several Maine rivers including both branches of the Penobscot, passing close to "Teddon".

In the 1840s Henry David Thoreau climbed Katahdin, which he spelled "Ktaadn"; his ascent is recorded in a well-known chapter of The Maine Woods.

The vast majority of incidents occur in the summer months, and the primary causes are leg injury, exhaustion, dehydration and disorientation.