There are quite a few articles and websites that go into detail about Mels Hole.

From Wikipedia: The legend of the bottomless hole started on February 21, 1997, when a man identified as Mel Waters appeared as a guest on Coast to Coast AM with Art Bell. Waters claimed that he owned rural property nine miles west of Ellensburg in Kittitas County, Washington that contained a mysterious hole. According to Bell's interviews with Waters, the hole had infinite depth and the ability to restore dead animals to life. Waters claimed to have measured the hole's depth to be more than 80,000 feet by using fishing line and a weight. According to Waters, the hole's magical properties prompted US "federal agents" to seize the land and fund his relocation to Australia.

Waters made guest appearances on Bell's show in 1997, 2000, and 2002. Rebroadcasts of those appearances have helped create what's been described as a "modern, rural myth". The exact location of the hole was unspecified, yet several people claimed to have seen it, such as Gerald R. Osborne, who used the ceremonial name Red Elk, who described himself as an "intertribal medicine man...half-breed Native American / white",and who told reporters in 2012 he visited the hole many times since 1961 and claimed the US government maintained a top secret base there where "alien activity" occurs.