Rock River COA

River Hill Country has numerous exposed rock faces of various compositions, most notably St. Peter sandstone. A very loose composition of rounded quartz, St. Peter sandstone erodes under the slightest atmospheric conditions. Returning to its original state as sand, the dry soil creates a unique substrate for flora and fauna to thrive in many areas in and adjacent to the Rock River COA. 
 
Currently, the Rock River COA hosts an array of protected natural areas. The largest, Lowden-Miller State Forest, is immediately adjacent to Castle Rock State Park, residing on opposite banks of the Rock River. Together this complex contains approximately 4300 acres of upland woodlands, bottomland forests, and mature  

conifer stands. In this riparian stronghold, pileated woodpeckers, many raptor species and cerulean warblers find suitable habitat tothrive and ultimately produce offspring. Up river, remnant prairies, savannas and woodlands, containing multiple state listed species have been protected by the Byron Forest Preserve District and the Prairie Preservation Society of Ogle County. Downstream, the Dixon Park District manages Lowell Forest Nature Preserve, a wooded bluff overlooking the Rock River and five miles of riverfront. Many segments of the entire Rock River COA are wonderful riparian corridors, aquatic and terrestrial, and ample opportunities exist to make it a healthy corridor in its entirety. ​