Definitely some kind of Caddis. Looks to have some stripes on the wing, so...I don't think it would be one of the Sedges. Sedges (a sub group of Caddis) usually have spotted/darker wings and get bigger.
Yellow Sallies are a small Stonefly, usually bright yellow with semi transparent wings that lay flat on their back and they often have a red dot of eggs at their tail. Their antenae are usually around 1/2 the length of the body or less.
Thank you! I agree now that you guys point it out, the wings are the giveaway, you have convinced me!
I saw a couple of them tumbling down the river surface and their underbody looked very yellow. I'm used to green or brown caddis, not yellow, so this made me wonder...yellow sally, which timing wise doesn't seem too out of place albeit a bit early. However, spring caddis, this river, all of the information you both pointed out, makes perfect sense.
On that note, the caddis there appear to be larger than I remember!!
According to Wikipedia there are 14,500 species of Caddis. There has to be a large range of sizes with that many. Add to that what I observed on the S. fork of the Merced in Yosemite, where 2 different sizes October Caddis were coming off the same week. According to a park entomologist October Caddis of the same species can hatch after 1,2 or 3 years as a nymph making for 3 very different sized flies.