People who reported feeling Monday night's earthquake north of Craig to the U.S. Geological Survey's National Earthquake Information Center:
Hill AFB, Utah/1/3
Analysts from the National Earthquake Information Center in Golden have adjusted the magnitude of an earthquake that occurred Monday night north of Craig.
Originally, the NEIC reported the event, which originated 12 miles north of Craig, as 4.4 on the Richter Scale.
It occurred about 8:55 p.m., the NEIC reported.
However, after more information became available and further analysis was conducted, the NEIC adjusted the magnitude to 3.7.
Don Blakeman, an NEIC earthquake analyst, said the agency typically releases a preliminary magnitude to get information out to the public.
"Sometimes the magnitude hasn't been looked at as carefully," Blakeman said. "Our mission is to get the information out as quickly as we can."
A 3.7, he added, is a non-damaging event.
"It's enough that people nearby will definitely feel it, but you don't expect any damage with a quake like that," Blakeman said.
By 5 p.m. Tuesday, 159 people in four states reported feeling Monday night's earthquake to the NEIC.
Most people, 138 of them, were in Craig and reported an intensity level of 3, which is a weak shaking that generally occurs with no damage.
Ten people from Hayden reported the event, and two people from Maybell.
However, there also were reports from all across the state - Aurora, Denver, Littleton, Golden and Fort Collins.
A person in Rawlins, Wyo., reported the event, as did another at Hill Air Force Base in Ogden, Utah, 347 miles from Craig. The furthest report came from a person in Lakin, Kan., 480 miles from Craig.
Craig Police Chief Walt Vanatta said about 80 residents called the Police Department on Monday night asking what had happened.
Many people told police officials their initial reaction was they thought a car had hit their home, Vanatta said, and some wondered if there had been an explosion.
The police chief said he did not know of any structural damage caused by the earthquake.
Monday night was the first earthquake in Western Colorado since a tremor measuring 3.8 on the Richter scale occurred in February 2006, five miles west of Glenwood Springs, according to the National Weather Service in Grand Junction.
In September 2005, a 4.1 Richter scale earthquake occurred about 14 miles northeast of Steamboat Springs, the Weather Service reported.
"They (earthquakes) are not every day occurrences, but we've had a few," said Joe Ramey, a Weather Service meteorologist. "They occur, and typically, they're very light here in Colorado."
Joshua Roberts can be reached at 875-1791, or firstname.lastname@example.org.