This one's from Ralston Purina's own Tom Mix Comics #1, from Sept. 1940. It was uploaded to ComicBookPlus by "editor." Pencils and inks are credited to Fred Meagher.
The continuing adventures of Red and Beaver were reprinted in Crackajack Funnies #13, 14 & 15 in 1939, as found on ComicBookPlus. They'll be back - as will the dastardly Ace Hanlon.