The stream fishing is where it's at. If you like sitting in a weedy mudhole in the middle of a cow pasture, by all means, fish the lakes. Also, north of Williams Lake there's won't be more than a handful of lake opportunities. The vast majority of angling opportunity in the north half of BC is flowing waters. Getting to Williams Lake is only 1/5 of your drive, don't try to cram all your fishing in the bottom piece of the trip just because it's what people talk about the most! This is a pink year, so virtually every river on the cassiar highway in the nass & skeena drainages will be stuffed with pinks. There's really not a whole lot specific information on that route that's been published. It's still largely untapped by the angling community as a whole. Only the odd fly guy like yourself on holiday cruises through it. Best advice you'll get is just 'bring everything' ... you'll find everything from fresh chinooks to rainbows, dollies, pike and grayling at that time of year. There's a lot of country. Standard BC rules apply: If it looks fishy, it probably is.