The fly fishing equipment you need for the Lower American River depends on the season and species for which you are fishing.
A 5 or 6 weight fly line will be the best choice for the majority of fly fishing. The larger species, such as the king salmon, will require a 7 to 8 weight fly line. While most fly fishing will require a floating, weight forward line, you will possibly need sinking, sinking tip, and shooting head lines depending on what you're fishing for.
9 ft medium-fast action 5 to 6 weight fly rods are the best choice for most of the fly fishing you'll encounter on the Lower American River. If using a 7 to 8 weight fly rod, you'll want one that's 9-10 feet long, with a medium-fast to fast action. If using a spey rod (either single or two-handed), choose one that is 12 – 14 feet long.
Fly reels with a good drag (usually a disc drag), and large arbor spools.
For small steelhead, use a 9 foot, 3X leader. Choose 10 – 12 lb test leader, in a 9 foot length for standard fly rod, and use one 10-1/2 to 15 feet for a two handed spey rod. Your leader should only be 4 – 6 feet long, if using a sinking line.
You will probably want a landing net, which should be very large if pursuing the winter run salmon and steelhead.
Choose Perfect Flies for your fly needs.