A swarm of central Idaho earthquakes that rattled Challis residents for more than a month appears to be dying out.
But seismologists say five portable seismographs have provided new information about the area that saw a sequence of quakes up to 4.9 in magnitude, peaking in mid-April.
Mike Stickney with the Montana Bureau of Mines and Geology based in Butte, Montana, says the earthquakes are occurring on a northwest trending zone on the west side of the Salmon River.
He says the quakes are at the northern tip of the Lost River Fault but it's not clear if there's a connection.
That fault caused Idaho's largest recorded quake, a 6.9-magnitude rumbling in 1983 near 12,667-foot Borah Peak.
Stickney says the portable seismographs will be removed in the middle of June.