The Canon City Daily Record reports William Shaffer entered his plea Friday and is scheduled to be sentenced March 5.
Authorities say 41-year-old Heather Ann Dunn was killed in the Aug. 16 crash three miles west of Howard on U.S. Highway 50.
Shaffer, who faces at least $9,000 in restitution costs, originally was charged with one count of vehicular homicide by reckless driving. That charge was dismissed.
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