The Lake it is Said Never Gives Up Her Dead When the Skies of November Turn Gloomy

Nothing like skimming the Children's Picturebook Price Guide when the days are slow and kidlit news postings few and far between. Recently they were doing a thorough examination of first edition copies of The Lorax when I learned about a sure-fire way of determining whether your copy is pre or post-1986 (rather than, say, looking at the publication page). It appears that one of the lines of the text was changed. From:

in search of some water that isn't so smeary.
I hear things are just as bad up in Lake Erie.

to

They'll walk on their fins and get woefully weary
in search of some water that isn't so smeary.

Apparently two research associates wrote him regarding the cleanup of Lake Erie. They just asked that he put the line in the past tense. Seuss when one further on them and changed the line altogether. Interesting.