The Redwoods to the Sea initiative protects the necessary old-growth forests and clean water for many rare aquatic and terrestrial wildlife species. The acquisition provides a transition zone (ecotone) between three very different forest types: redwood, Douglas fir/mixed hardwood, and upland coastal. Because the area is so large and because significant changes in elevation gradients exist, habitats within the protected area vary greatly. This elevation variation sustains numerous microclimates. Differences in temperature, aspect, and forest type provide diverse habitat for species dependant on specific niches.

Old-growth forests are increasingly rare ecosystems in the Pacific Northwest. The intensity with which industrial landowners in search of short-term profits are liquidating the old- and second-growth forests in Humboldt County's "Redwood Empire" is staggering. Luckily, the species of plants and animals dependant on forests with many strata (levels) of foliar canopy will be able to recolonize in Gilham Butte's recovering forestlands. (Microclimates and niches that exist in certain strata are not found within second-growth and third-growth forests.)

Species with large home ranges--such as mountain lions, black bears, martens, fishers, and northern spotted owls--will benefit greatly from the wildway in the Gilham Butte area. Other rare and endangered wildlife that will benefit are salmon and steelhead (which thrive in the five acquired Gilham Butte watershed tributaries for the Mattole river and South Fork Eel rivers), goshawks, golden eagles, pileated woodpeckers, western pond turtles, Pacific salamanders, red-legged frogs, tailed frogs, southern torrent salamanders, and red tree voles.

The Mattole is one of the most southerly river systems in the Pacific Northwest where salmon have not been extirpated in the last century. This fact most likely results from the longest running citizen-based native-salmon-rearing and enhancement program in the country, which grew out of the visionary efforts of the Mattole Salmon Group in the 1970s. In addition, because of its remoteness, the Mattole is one of the California waterways least impacted by the genetic manipulation of state-run stocking programs.