Picking The Location
While you can find gold in all three branches of the American River, it is the south branch that is known for its concentrations of the metal. Getting to the river is your first trick. There are parks that allow gold panning but going where everyone else is panning doesn't get the best results. It is difficult to find land access to the river. The best technique for finding a spot to pan is to go in by boat or raft and find areas along the river from the river itself. Otherwise you will have to hike in wherever you can find open land or settle for a day at the park.
Where To Pan
Look for mine tailings in the hills above the river. Gold weathers out of old mines faster than out of untouched hills. Pan down river or at tributary streams running into the river below the tailings. You are looking for areas where fast currents slow enough to drop the gold they carry. Places where the bedrock is shallow are good, and with a pair of goggles you can often see gold laying on the bedrock or stuck in cracks in the rock. Shallow areas where rocks produce a washboard effect in the water are other spots to pan. Look under rocks that are large enough to divert the current.
Main Equipment
Dredges are currently (2011) illegal in California. Pans are OK and so are rocker boxes and sluices. If you are using pans alone, you may want to have an electric gold concentrating pan such the Desert Fox with you. Electric pans save you time by "panning" a load while you collect more and pan it down to sand. You also need to take a shovel to dig, a crow bar to move rocks and classifiers to separate the larger rocks from the sand. Swim goggles, crevice tools and a suction tool are also handy for areas where bedrock is shallow.
A Few Special Tips
Flowing water can be merciless to panners. Take a 2- or 3-foot-square sheet of metal or wooden board with you. Stand the sheet on the upriver side of the area you are panning and anchor it with rocks to form a wall that water will have to go around to keep the current diverted from your digging area. Water pipes are natural sluices. Where tributary streams flow through pipes under roads, place a burlap or nylon sheet below the downstream side of the pipe. Use a broom or squeegee with an extendable handle to push debris through the pipe and into your net. Burn the net later and pan the remains.