The US Forest Service is proposing a massive project in a national forest in Michigan that would log land roughly the size of Detroit, expand gravel mining and build roads. The Silver Branch Vegetation Management Project would span about 40 miles from north to south on the eastern edge of the Ottawa National Forest. The area includes habitat for the endangered northern long-eared bat, one of several reasons environmental groups have raised alarms. The proposal includes a wild rice seeding project, improvements to campgrounds and lake access and attempts to bolster habitat for the protected Kirtland’s warbler. The whole thing is projected to last around 30 years, with periodic reviews. …national forests serve multiple purposes [including] recreation, wildlife habitat and timber. Ottawa National Forest officials say the Silver Branch project is not primarily about logging, it’s about getting the right tree mix for forest maintenance and health. However, the project has drawn concerns from a wide range of groups.