This small area of undeveloped Willamette River shoreline, along the Willamette Greenway, is a good example of the natural environment of the river. The park is deciduous woodland planted for butterflies and insects; it was named 'butterfly' for its importance as a habitat for butterflies. Vegetation includes native grasses, wildflowers, and dogwood. Butterfly species include mourning cloaks and orange sulphurs. The park is frequented by various birds including cedar waxwings, killdeer, orioles, and chickadees. An interpretive sign is located at the entrance to the park.
The area was formerly a gravel parking lot and refuse area for the Macadam Bay Club. In 1991 volunteers began planting wildflower seeds harvested from the Columbia Gorge.