"The Source" of the NF of the American River is a trickle of water coming out of the ground out back of the Sugar Bowl Ski area, SB is just off Hwy 80 on your way to Tahoe/Reno. Walking from the Hwy 49 bridge out back of Auburn to the source, well one can not walk all the way. Seems some nearly straight up cliffs at Lovers Leap Gorge tend to cause some folks to go around. It could be done right now as the river is quite low but you will be swimming and towing your gear, of course if you have a Kayak then you could just paddle up stream though there will be a great deal of portaging. From LLG you come into Green Valley, go through the next gorge to enter the Euchre Bar area and not long after going under the foot bridge you will need to portage around some very BAD water - actually the water it wonderful it is just that a major portion of the cliff fell off and it will kill you if you try to go through it. From there, by water, you reach the Italian Bar Area (only soft drinks made with water served there), next is Mumford Bar, then Beacroft and a 15' + waterfall you will need to portage around on the left side going up river before the solid rock gorge with the 15' + waterfall at the upper end of it. After Beacroft there will be a long paddle till you reach Sailor Flat. Now up river from Sailor is some more river then it all goes underground and this is where the progress gets really hard as now you have to go over gigantic river boulders to make your way up the dry river bed. At some point you will notice Bear Poop on many of the boulders. Every year as the water decreases, pools in the area of the bear poop dry up leaving trout for hungry bears to find and eat and because bears will poop where it is convenient as well as wherever they want, they do it on the boulders. As you reach the back end of the canyon you will begin to find some water again. At the top of this creek is a pool about 60' in diameter with a 70'-100' waterfall plummeting into it. The last time I saw it the pool was likely 30' deep right under the waterfall. Snakes like this area as it is easier for them to catch the trout so be on the lookout for them and yes they do swim.
Climbing the waterfall takes you to the upper reaches of the NFAR though by now it is a creek. Early in the year Kayakers put in way up this creek at "The Ceaders" which at that time of year it is a raging beast and go all the way down to the Colfax Bridge's. They hit it at say around 2000 cfs when the water temp is likely 40 degrees or a touch lower. I would not do that for all the tea in China as they go over All of the water falls. Of course a lot of the river boulders are well under water, maybe even the ones up river of the Euchre Bar bridge, maybe! It has to be one exciting ride but I will pass on it. In the valley areas the fishing should be OK, in the gorges it is questionable to nonexistent save for the gorge between Italian and Mumford as there is at least one good spot there, the pool just down river from the hardrock mine on the left wall (going up). However the 2008 fire has caused a Huge weed growth along the valley trail and I am not certain just how far down river the burn area extends but it ends between Beacroft and Sailor Flat. Ugly trail hiking in that mess!!!!!!!! Some beautiful water and canyons and side creeks, all of it old mining country and some of it is amazingly Rough. Bears, Bob Cats, Rattle Snakes, Deer so likely Mountain Lions, some night time animals, banana slugs (empty your shoes in the morning or pay the price), black beetles that bite and leave a very sore bullseye from the bite and bears(yes I've repeated myself but with good cause). The bears will attack your hanging food bags and will destroy tents unless you leave them open when you are not in them. They are a pain in the butt! The trout like worms and lures IF you can find any Trout as the river has been over fished since the late 70's, quite a shame. Blackberries once it gets hot enough for them to ripen and they are GOOD! I've enjoyed BDU Boonie hats full over the years so I know why the bears like them. Wild grapes as well. Foxtails, small stickers and lots of PO so bring your lotion. Oh, and skeeters (mosquitoes) and bats and dragon flies and butterflies, "Oh My".
So Fullpan, that is a little bit of what it would be like to go all the way to the source of the NFAR. Anyone doing that would be a "Real Man" by the end of the trip even if she were a woman to start with!...............................63bkpkr