Apple River Canyon

State Natural Area (No. 145)

Location: St. Croix County. T31N-R19W, Sections 21, 28. 160 acres.

Access: From the intersection of County Highway I and State Highway 64 in Somerset, go west on Highway I 2.4 miles, then continue west on 192nd Avenue 0.85 mile, then north on 42nd Street 0.3 mile. Walk northeast on an access lane into the natural area. Or from its intersection with 192nd Avenue, continue on Highway I another 1.7 miles, then southwest on 208th Avenue 0.6 mile. Park along the road and walk south into the site.

Description: Apple River Canyon features a deep (100-140 feet), narrow (150 feet) gorge along the Apple River about two miles upstream from its confluence with the St. Croix River. The Apple River is a shallow stream flanked by steep high cliffs on both sides. The canyon lies a few miles south of the limits of Glacial Lake Grantsburg, and presumably the gorge was formed during the period of drainage of the lake. A cross section of the gorge reveals - from top to bottom - thin layers of glacial outwash and Oneota dolomite (Ordovician), a massive layer of Jordan sandstone (Cambrian), Lodi shale (Cambrian), Nicollet Creek dolomite (Cambrian), and Franconia sandstone (Cambrian). The vegetation is quite interesting due to the nearly east-west orientation of a segment of the gorge, creating north and south walls with contrasting sunlight, moisture, and temperature conditions. On the upland to the north is an oak forest: on the south-facing upper slope a strip of prairie grasses; on the south-facing cliffs a few lichens and mosses; on the lowest talus slope a floodplain forest; on north-facing talus a northern dry-mesic forest; on northern cliffs, cryptogams; and on the upper slope a narrow prairie. Apple River Canyon is owned by the DNR and was designated a State Natural Area in 1978.