The Wildfire Management Branch and the Conservation Officer Service hope tips from the public will lead them to the person who sparked the fire at Spatsum Creek.
The blaze scorched 14 square kilometres of brush since it broke out on April 27, and, at one point, forced the evacuation of a large rural area east of Ashcroft, about 300 kilometres northeast of Vancouver.
Wildfire investigators say they have determined the fire was caused by humans, but they can't tell if it was deliberately or accidentally set.
They want to speak to anyone who may have information about the blaze and add that they are encouraged by tips they have already received.
Causing a wildfire carries a maximum $1-million fine and a three year-prison term, and a Cariboo-area man is currently before the courts appealing an $860,000 fine to cover firefighting costs after a campfire on his own property flared out of control in 2010.