The Superior National Forest has identified stands of timber worthy of being set aside as forest preserves. Now the Minnesota Department of Natural Resources, which owns land within the national forest, may begin timbersales and road building in the midst of one of the most highly valued stands. Minnesota Public Radio's Mary Losure reports. The Superior National Forest survey lists relatively undistubed timber stands within its boundaries and ranked them as potential preserves. A 28 square mile area known as "Big Lake Seven Beavers" was high on the list. The survey notes that"the size, diversity, and lack of disturb