Alan, I only fish once in a while so I really don't know, but some local sites indicate that salmon are in the river in September. Depending on your prowess with bait and lures, I'd recommend a guide to hook you up with a sure fire rig and deal with the location, regulations, licensing, etc.
My favourite and most recommended hike in the Chilliwack area is Mt. Cheam – spectacular views---but its a 9 kilometer (6 mile) round trip after a long rough drive partway up the mountain. My son would do it in 6 hours without breaking a sweat, not so much for me
Here's a list of a few of the other hikes in the area and reviews. hiking in North America, hiking routes in North America, day hikes in North America, hiking trails in canada with GPS download