The article's writer, Steve Wilson, wrote a well-known book about the Spider Rock treasure. He also wrote a terrific book on Oklahoma treasure tales - highly recommended.
Interesting story.
I can't say I am well versed on the story. However I can confirm the claimed discoverers of the stone existed. Dave M Arnold was a Farmer living in Texas in 1900. He married had children in 1920 and was still recorded living in Texas until the 1930s. His alleged financial backer Dr Caleb Lafond Terrell did exist. However his date of death in not known at this stage. There is only one record of him in the 1870 census.
Amy