Pretty River Valley Provincial Park is a nature reserve that straddles the escarpment southeast of Blue Mountain. The Bruce Trail and several side trails run through the area where mossy limestone, fern covered outcrops and hidden crevice caves abound. The cave passages are very narrow and fun to explore. Petun Conservation Area is another rugged trail area located just 1 km north of the Pretty River Valley trails. The park is also accessible below the escarpment from Nottawasaga Side Road 30/31 or Pretty River Road. It is not advisable to venture off trails in winter due to the danger of stepping into snow covered crevices.