Point the van east out of Abbotsford and Cultus Lake is about half an hour up the valley, a big warm lake with sandy beaches at Entrance Bay and Maple Bay and forested mountains standing over the water.
Sleep on the lake at Entrance Bay or the year-round Delta Grove loop, and book it up to three months before arrival at camping.bcparks.ca, because July and August weekends go within minutes of the 7 am release.
The park is on the Chilliwack side of the valley, so its campground loops and fees sit on the Chilliwack lander. From Abbotsford, take the Yarrow exit, Highway 1 Exit 104, and follow the Cultus signs about 16 km down the Columbia Valley Highway.
Golden Ears and Alouette Lake, west past Maple Ridge
Golden Ears Park and Alouette Lake are the westbound overnight, up past Maple Ridge and covered on the Maple Ridge lander. Other van bases around the province sit on the British Columbia hub.
Vedder River Campground, if the loops are full
Cultus runs its loops with no power, so if you need hookups or you arrive late without a reservation, the fallback is Vedder River Campground, about a 10-minute drive on the Chilliwack side with 30-amp sites, hot showers, and check-in until 10 pm. If you'd rather plug in and travel in something larger from the start, the RV rentals in Abbotsford run bigger and come with hookups.