The Touchstone is an alien device from Madrona, probably created by the same advanced race that originally terraformed the planet. It can control and maintain the weather when the high priest turns a series of calibrated rings which determine meteorological conditions over the entire planet's surface. When it was stolen by rogue operatives of the NID off-world operation, the catastrophic weather conditions on Madrona nearly destroyed the planet, and rare weather disasters began to occur on Earth. SG-1 traced the Touchstone first to the Nevada desert, and then to a secret facility about 40 km west of Parowan in Utah where the beta stargate was being used by rogue operatives to steal alien technology. SG-1 returned the Touchstone to Madrona and the planet's weather was restored.
Cross Reference: La Moor, Madrona, Madronans, Harry Maybourne, NID Off-World Operation, NID Rogue Operation, Roham, Whitlow
Episode Reference: Touchstone