Richard Richmond notes this cover has the same essential composition as the cover to M-G-M's Lassie (Dell, 1950 series) #16.
Story does not involve Timmy, nor Corey the forest ranger.
Gaylord Du Bois script credit as per page 42, Gaylord Du Bois's Account Books, Sorted by Title, compiled from the original account books by Randall W. Scott. Script identification by David Porta (September 2013). Account Books entry states: "Lassie's Night Watch. 14 half pages. For March of Comics. Sent February 21, 1973."
This is the last Gaylord Du Bois Lassie script.