The poem starts with a wrecked landscape: forests cut, then burned, then washed away by floods. Only after that does it bring in the lion, and the order matters. By the time she appears, the land that sustained her is already ruined, and she is starving, her bones showing through her hide.
The speaker tells this in a flat, reportorial voice, almost like a local history. We hear the lumbermen's claim that she had been prowling and had even stalked one of them, but the poem undercuts it with a blunt line: "though she had not." The speaker names the man who shot her, Thomas Anson, which makes the blame specific. The final image, of him pumping bullets into her "crumpled form / to make damn sure," is the cruelest detail, because she was already beaten.
The mood is grim and quietly angry. The speaker doesn't shout. Instead the plain facts, and the fear that outlasts the danger, do the accusing.