Awesome, I was searching for this song a couple months ago, "I may not pass this way again." I might have tried more than once to find this song.

I did a lyrics search and kept finding songs by Seals and Crofts, and Perry Como. But from some of the entries, it looks like it was written by Rod McKuen. And someone who google book search found it was in "Exploring Music" by Eunice Boardman and Beth Landis, New York: Holt, Rinehart and Winston, 1971, page 9.

Thanks to everyone who tried to figure this one out! I remember this song from my music class in 5th grade, 1987-88. And also the Kookaburra song and the Erie Canal song, as others have mentioned in this query.

I do remember looking at the credits, back in 5th grade, to the songs from the elementary school song books. And I remember seeing that some of these songs were folk songs from the early 70's, maybe early 60's.