Blue Hills Felsenmeer

State Natural Area (No. 74)

Location: Rusk County. 75 acres.

Access: Access is restricted due to the sensitive nature of the site. Contact The State Natural Areas Program or Rusk County Forestry (715.532.2113) for more information.

Description: Blue Hills Felsenmeer features talus slopes and is an outstanding location for geological interpretation of glacial action. The natural area consists of several small valleys, strewn with lichen-covered rocks, on the southwest side of the Blue Hills. These unusual features required unusual circumstances to develop. Early Woodfordian glaciation covered the Blue Hills and cut canyons on the western flank when the glacier retreated. The late Woodfordian glacial advance covered all but this western portion. The tundra climate in the area led to excessive frost activity, leading to the development of several features. The felsenmeers (meaning "sea of rocks") were formed by excessive frost activity. Quartzite, being a brittle rock, is very susceptible to frost wedging. Continuous wedging over time formed slopes of angular rock rubble. Some slopes are very stable; others have six-foot-high ridges of "talus moraine" formed at the base. Cold air emanating from deep within the slopes maintains a tundra-like environment. Several species with boreal and tundra affinities are still present, and the lichen flora is diverse. Blue Hills Felsenmeer is owned by Rusk County and was designated a State Natural Area in 1969.