As Mexico was being jolted by a series of moderate-to-strong earthquakes today, Wyoming got into the earth-shaking act, too.

The USGS recorded a magnitude 4.5 near Sleepy Hollow at 10:11 a.m. MT (12:11 p.m. ET). Turns out it was caused by mine blasting.

The “Fake Quake of 2012″ was “really an amplified echo of an unusually large mine blast,” about 17 miles south of Gillette, the Casper Star-Tribune writes. A USGS geophysicist based in Golden, Colo., said the explosion actually registered as magnitude 3.0.

Locals said they didn’t feel a thing.

“The only question now is: who set off an explosion that big at 10:12 a.m. somewhere in rural Campbell County?” the paper wonders.