Matthew Darren Kanzig, 46, of Slave Lake, Alta., is also charged with two counts of dangerous operation of a motor vehicle causing bodily harm.
RCMP say a northbound truck hit a compact car Thursday morning on Highway 44 north of Westlock.
The crash in poor visibility killed a 23-year-old woman, a four-year-old girl and a one-year-old boy.
A woman and another young boy who were also in the car were seriously injured and taken to hospital.
Kanzig, who was also hurt, is to appear in Westlock court Wednesday.
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