Brant Brook Pines is an old-growth stand of large red pines along the St. Croix River estimated to have originated in the mid 1880's. The northern dry-mesic forest is dominated by red pine with white and jack pines, Hill's oak, basswood, large-toothed aspen, and white birch. A narrow swale of black ash nearly divides the area. On the elevated river terrace above the pines is a dense forest of small oaks while a more mature swamp hardwood forest of oak, black ash, and red maple occurs on the low terrace below the pines. The herbaceous layer contains numerous fern species including bracken, spinulose wood, and ostrich along with common early summer species such as wild geranium and columbine. Brant Brook, a steep gradient, sandy-bottomed stream deeply incised into the river terrace flows through the site. Fed by numerous seeps, the narrow cold water stream supports native brook trout. Two uncommon birds, black and white warbler (Mniotilta varia) and yellow-throated vireo (Vireo flavifrons), inhabit the forest. Brant Brook Pines is owned by the National Park Service and the DNR. It was originally designated a State Natural Area in 1979 and expanded in 2002 to include the St. Croix National Scenic Riverway.