Weather in Baxter State Park can be characterized primarily by its variability; snowfall can occur any month of the year, and temperatures can and do fluctuate widely around the averages.

[citation needed] Baxter State Park has a diverse population of wildlife, the most common of which are the moose, the black bear, and the white-tailed deer.

The many marshes and bogs of the park serve as habitats for such animals as beaver, muskrats, river otters, and raccoons.

In 1920, eventual Governor Percival P. Baxter participated in an expedition to the top of Mount Katahdin, led by Burton Walter Howe (then-chairman of the Aroostook county Republican party), to determine its feasibility for the site of a national park.

The expedition included not only Baxter, the presumptive choice for President of the Senate, but also Charles P. Barnes, who was widely regarded as the leading candidate for Speaker of the House of Representatives of Maine when it convened in January 1921.

The unexpected death of Governor Frederick H. Parkhurst on January 31, 1921, triggered Senate President Baxter's elevation to the governorship.

This unforeseen development dramatically changed the political fortunes of Baxter's park proposal.

William F. Dawson's illustrated lecture, scheduled by Baxter for February 2, 1921, was canceled, and in its stead legislators were filing past Parkhurst's coffin laid out in the Capitol's rotunda.

[6] With failed legislation, Baxter started to use his personal wealth to purchase land and pieced together the park by himself.

He officially donated that parcel to the State of Maine in 1931 with a condition that the park be kept as wild in perpetuity.

Baxter wrote of the area: "Man is born to die, his work short lived; buildings crumble, monuments decay, wealth vanishes, but Katahdin, in all its glory, shall forever remain the mountain of the people of Maine.

"[9] In 1979, volunteers in the Maine Youth Conservation Corps created the mural on Pockwockamus Rock,[10] located about 2.5 miles from the south gate (45°47′56″N 68°53′40″W / 45.798977°N 68.894338°W / 45.798977; -68.894338).

Only northbound long distance Appalachian Trail hikers can stay in the park without reservations; they are limited to one night's stay at The Birches camping area, which is limited to the first twelve hikers to sign in at an information kiosk several southbound trail miles away just inside the park's southern boundary.

The park also includes a Scientific Forest Management Area of 29,587 acres (120 km2) located in its northwest corner.

Fire protection is provided by the Maine Forest Service; waste disposal and recycling is addressed through the park's Carry-In, Carry-Out policy.