Since John Huddleston discovered the first diamonds here in 1906, people have wondered what lies beneath the volcanic soil in Southwest Arkansas and how deep and large the diamond deposit is. From 1990 to 1997, Arkansas State Parks and several international mining companies conducted tests in two phases to answer those questions. In Phase 1, core samples collected with a drilling rig measured the size and shape of the diamond-bearing crater. The crater was found to be the eighth largest diamond deposit in the world, reaching more than 669 feet deep and containing more than 46 million cubic yards of ore. In Phase II, mining companies processed more than 9,000 tons of ore and recovered 210 diamonds weighing 47.48 carats. This confirmed that the large deposit contains many diamonds, but the gem quality was not commercially profitable at the time, so interest in further testing diminished.