has it been the habitat for any animal?
Ground squirrels, mule deer
Belknap Crater
mule deer 
what is belknap crater? Is a shield volcano where is it located? Located in Linn County has it ever erupted? It had four Holocene eruptive periods confirmed by geological evidence
wiki:7510661
Belknap Crater [SEP] Ecology
Along the trail to Little Belknap Crater, there is a tree island with lodgepole pine, mountain hemlock, and true fir. There are also ground squirrels running around on lava flows from Belknap. Along the Oregon Skyline Trail, which passes west of Belknap, there are black-tailed and mule deer as well as lakes stocked with Eastern brook trout Along the western flows produced by Belknap, there are several dozen tree molds, which range from in diameter and in depth. Some fell into the lava, forming hemi-cylinder-shaped trenches up to in length. Taylor (1965) identified a system of radial roots that were charred from the lava under soil at one of the molds.