[CALIBK12] Book title?

[Mary Thomas]

A teacher is looking for the title of a book she read in the mid to 
late 70s. She thinks it was published by Scholastic - or at least sold 
through them. She doesn't know the title or author. She remembers that 
it was about a group of girls who went on a walk or a hike, out into 
the woods perhaps, maybe to a pond or waterfall. Maybe swimming. And 
then they all disappeared. The story was set at the turn of the century 
in America. She lost the book before she finished it and wonders how it 
ended.

Any help will be appreciated.

Mary Thomas
Library Media Specialist
Redwood Middle School
Saratoga, CA