The Acadian Plains and Hills is an ecoregion that is highly forested area covering much of about half of Maine in the southern and eastern areas. There are also a small area in Quebec, a large adjacent areas in New Brunswick which wraps around the Bay of Fundy and across the Nova Scotia shoreline of the Bay of Fundy.

This region has mostly rolling terrain, with hilly uplands, plains interspersed with isolated hills, and rolling lowlands. Bedrock outcroppings are widespread, and there are also rocky glacial moraines throughout, as well as numerous glacial lakes. There are both perennial streams and larger rivers, and the drainage pattern is typical of glaciated regions, with irregularly rugged terrain from glaciers disrupting the drainage network, and few areas of well-developed dissected terrain.

This region is for the most part, sparsely populated, but there are a number of towns throughout. Forestry is the most common land use here, although there are some areas where agriculture has become important. Agriculture tends to concentrate along the St.John River where the soil is richer as well as in the Central Maine Embayment. The most important crops here include potatoes, oats, buckwheat, barley, broccoli, and hay. The coastal area are economically important due to tourism and recreation, especially towards the southwestern reaches of this ecoregion, and becoming less important farther east. Although tourism represents a relatively small portion of total land use, it represents a much larger portion of the economy of this ecoregion.

On the southwest of this ecoregion, the adjacent ecoregion, the Northeastern Coastal ecoregion, is more densely populated and supports a warmer coastal climate. This border between these two ecoregions is not only abrupt, but it is marked by a clear geologic transition from a rocky coastline in the northeast to a flatter coastline with greater fine sediments and abundant coastal marshes in the southwest.

To the northeast, this region borders and partly surrounds the Maritime Lowlands. Inland to the west and north, this region is bordered by the more rugged Northeastern Highlands; a different portion of this same region also borders this region to the southeast in Nova Scotia.

Algonquin Speaking people

Blackwoods Campgound, Acadia National Park

Cadillac Mountain

Acadia National Park