Strataca is an underground museum in Hutchinson, Kansas, built 650 feet below the prairie inside an active salt mine and the only salt mine in the United States open to tourists. Set within a vast rock-salt deposit formed about 275 million years ago, it occupies part of a mine that began in 1923 and uses the room-and-pillar method. Developed from Reno County Historical Society planning in the late 1990s, the museum required a new shaft completed in 2004 and 2005 to improve access. Today it combines exhibits and tours with a rare view of Kansas’s salt industry, active mining, and the immense age of the deposit.