Pine Bend Bluff Scientific and Natural Area. Pine Bend Bluff Scientific and Natural Area - Mississippi National River and Recreation Area (U.S. National Park Service) Pine Bend Bluff provides spectacular views of the Mississippi River from bluffs overlooking the river valley. The park consists of savanna, oak forest, and dry prairie. Native grasses and forbs, including spring flowers, are also attractions. Pine Bluff SNA is 256 acres in size. Activities. Since this is a state scientific and natural area, low-impact only activities are allowed. Hiking, nature study, bird watching, and photography opportunities abound. Hours, Directions, and Contact Information.