This one-of-a-kind site, with its unique geologic formation, represents an example of native vegetation on serpentine soils at low elevations in the Western Cascades.  Ultramafic rocks such as serpentine (an olive-green, heavy rock) are high in magnesium and weather to produce sterile soils inhabited by specially evolved plants.  Dwarfed trees, junipers and serpentine ferns highlight the odd plants which persist at Olivine Bridge.  The 148-acre site also supports a mixed conifer forest.  (Skagit County)