Sigma

Going up about 1/3 of the way is an easy scramble. At about this point, you reach a small ledge where you can stand. If you look straight up from here, you'll see the rock bulging out a bit. There's a thin, vaguely C-shaped flake to the left of the bulge, which I believe is legal for this route. I tried using that, but failed. Good luck to you.

This route is left of Double Traverse.

To get to the bottom of the route, climb up from the water's edge to a broad ledge (10+ feet wide). Start left of Double Traverse and pretty much go straight up. There are a couple of small trees growing on ledges, I went right of them.

There are two bolts at the top near the edge. We used those as an anchor for Double Traverse, and reused them for the climb up Sigma. Unfortunately, that resulted in an uncomfortable pendulum at the crux of Sigma. You will probably want to anchor to the left of the anchor for Double Traverse, so search for trees further back, and bring some long slings.