I was very impressed by inner mesquite bark. Last year I was stripping it from trees that got killed in camp burn outs over the summer.
A note on agaves and yuccas:
They dont occur naturally on the floor of the valley anymore, but there are some big blue agaves in brawley you can go grab.
Its easier to remove the fibers from the leaves if you cook it first.
I Boil the shit out of them for 5-6 hours, But I’ve read the native peoples would make a large fire then bake them overnight on the coals, probably more efficient this way.
Anyway then pounded the leaves with a rock to soften the flesh. Go to a stream with some good flow(the lower canal) pull off an inch thick chunk of fiber and flesh , pinch and run your fingers down the length a few times, like your stripping a rosemary sprig. The blue agave juice makes your skin itch, so rubber gloves are reccomended.
Helps to have a rack near by to hang the clean fibers on so they dont get all tangled while they dry
Also waxing the fibers with pure bees wax makes the twisting easier.