The travel time from Chilliwack (Highway 1 exit 119) to Chilliwack Lake Camp is 1 to 2 hours depending on the vehicle you are driving and how you drive on rough roads. The last 8km of the journey is very rough and could take 45 minutes if in a small car like a Honda Civic. A truck or 4x4 is a preferable vehicle.
Google directions from Highway 1 exit 119 (Vedder Rd) in Chilliwack to Chilliwack Lake Camp
(Note that you will not have cellular service for the whole journey): https://maps.app.goo.gl/HeiUyHsfhHrMHJgR8
More detailed directions:
On Highway 1 going through Chilliwack, take exit 119 (Vedder Rd) south (towards Sardis)
Travel 5 km on Vedder Rd to Vedder River crossing - do not cross the bridge!
Before the bridge turn left (east) on Chilliwack Lake Rd
Travel 40.6 km to Chilliwack Lake Provincial Park campground
Go straight past the campground onto a very bad unpaved service road
Travel 8 km southeast and then south
At about the 7 km mark, turn right over Paleface Creek - do not go up the hill
Take the first right soon after that through a yellow gate into the camp