Complex sentence: The park protects two State Natural Areas including Brady's Bluff Prairie and Trempealeau Mountain, a cone-shaped mountain surrounded by water, which the Native Americans of the area considered sacred and used as a landmark for meetings.
Split into simpler sentences: The park protects two State Natural Areas including Brady's Bluff Prairie and Trempealeau Mountain, a cone-shaped mountain surrounded by water. The Native Americans of the area traditionally considered the mountain sacred and used it as a landmark for meetings.