AW #58: Beware of the Signs!

Evelyn Mervine at Georneys is holding another Accretionary Wedge carnival (two in a row!), this time it's AW #58: Signs! I was first thinking of some geographic signs along the lines of her original signposts meme, and realized the ones I was thinking of consist of license plates rather than mileage signposts, and that all the ones I have are probably non-digital and currently a bit hard to reach (nevertheless will try to post some when I'm not quite so busy). Instead, I dug up a sign from a trip to Crater Lake a few years back.

Hard to say whether this sign on a very steep part of the west rim of Crater Lake is to warn one away from the danger of the steep slope, or a warning that the mountain (cinder cone or entire caldera?) might blow!

Glacial grooves and striations, field sandal for scale.

Either way, if one persists past the sign in true geological fashion, one will find a great exposure of glacially striated and grooved volcanic rock. Read a little more about the glacial history of Crater Lake here.