hear through the grapevine

The story

From the Grapevine, a telegraph line that ran from Placerville, California, to Virginia City, Nevada, beginning in 1859, and that was loosely strung from trees so that it curled like the vines of California grapes. In 1861 it was replaced by the Pacific Telegraph, which was strung from poles, and during the American Civil War "grapevine telegraph" became proverbialized to refer to poor and rumor-prone communications in areas cut off by the war.