Large round silver UFO in Peace River Valley 1966-67

My dad and mom and I were returning to Hudson's Hope from Fort St. John where we had been shopping.  Dad was driving, mom was laying down snoozing in the back seat of the car.  I was in the right front passenger seat. We were going up a hill and off to our left suddenly a large light came on and lit up the hill and the inside of our car.  Dad pulled over and stopped the car and told mom to get up.  The light went out.  There was no sound, nothing then the light came back on again and off again and I guess took off. This thing was round and was roughly as big as our car.  The light it emitted was rather like looking at a brilliant silver dollar, it did not hurt your eyes to look at it.  We could make out no distinct features and it made no sound.  The area we were in is the Peace River Valley and the bank at that location falls away steeply about 600-700'.  The evening was dark, no light, no snow on the ground but there were a few large lazy flakes falling.  My dad went to the RCMP and asked if they had "heard of a helicopter in trouble or anything" no they hadn't and dad never persued it.  My dad and mom owned their own business at the time and were very reliable people and wished to remain that way so we never talked outside the family about it but privately we thought it was a UFO not from this world and that they were here checking the mega project that was underway at that time (the W.A.C. Bennett Dam Project) where before there had been nothing but a few farms in this remote area of British Columbia, Canada.
Date is approximate.  PD