Increases in insurance and public liability cover have left many of them facing a funding shortfall.
James Hutton's visit to Siccar Point in the 1780s led to a change in the way the history of the Earth is understood.
Five facilities will continue to operate next year after Scottish Borders Council agreed a new plan.
A Peugeot 5008 and a white Ford Transit van crashed on the A1 between Cockburnspath and Grantshouse.
A special meeting will be asked to keep the under threat sites open for the next school year.
Parents in the Borders say they are "disheartened" that plans to shut six sites were not put on hold.
The local authority in the Scottish Borders says another six sites could close in the summer.
The Southern Upland Way covers more than 200 miles from Galloway to the Scottish Borders.
John Paul, from Duns, was taken to the Royal Infirmary of Edinburgh on Sunday but died on Tuesday.
