evidence: But there is more to this area than the Tower. Life thrives around its base. Here in Wyoming's northeast corner, Black Hills pine forests merge with rolling plains grasslands. At Devils Tower you can see every phase in the process of establishing a forestfrom bare rock to pines. And because mountains and plains converge here, you may find a great variety of birds. More than 150 species have been countedincluding hawks, bald and golden eagles, prairie falcon, turkey vulture, and American kestrel. No one will miss the brightness of the male mountain bluebird, the industriousness of the nuthatches, or the feistiness of the black-billed magpie. Predominant mammals are the white-tailed deer and black-tailed prairie dog. You can spend hours watching busy, playful prairie dogs in their "town" on the grasslands below the Tower. [...] About 60 million years ago molten magma was forced into sedimentary rocks above it and cooled underground. As it cooled it contracted and fractured into columns. An earlier flow formed Little Missouri Buttes. Over millions of years, erosion of the sedimentary rock exposed Devils Tower and accentuated Little Missouri Buttes. The Tower rises 867 feet from its base and stands 1,267 feet above the river and 5,112 feet above sea level. The area of its tear-drop shaped top is 1.5 acres. The diameter of its base is 1,000 feet. [...] Devils Tower (Wyoming, USA): A lava coulée emplaced into a maar-diatreme volcano? (P. Závada, P. Dedeček, J. Lexa and G.R. Keller, extract from Geosphere, Vol. 11 No. 2, 2015, ©Geological Society of America)