Minnesota has four ecological provinces: prairie parkland, in the southwestern and western parts of the state; the eastern broadleaf forest (Big Woods) in the southeast, extending in a narrowing strip to the state's northwestern part, where it transitions into tallgrass aspen parkland; and the northern Laurentian mixed forest, a transitional forest between the northern boreal forest and the broadleaf forests to the south. These northern forests are a vast wilderness of pine and spruce trees mixed with patchy stands of birch and poplar.