 Indeed, the Bob Marshall region is the most ecologically complete mountain wilderness in the country, according to Wolke.Although renowned for excellent fishing and backpacking opportunities, most of those that enter the wilderness complex do so on horseback and there are outfitters that provide guided pack trips into the region.The Bob Marshall Wilderness Complex is also well known for being prime grizzly bear habitat, and the population density of this species is higher there than anywhere else in the lower 48 states.