Not Amanita Phalloides (wrong coloration and shape) nor Bisporgera (not found here, but common back East), Correct about it being one of the most deadly mushrooms out there. You found Amanita Ocreata, the Western Destroying Angel.
Continuing the theme of really pretty things that will kill you -- along the Hondo Canyon Trail in the Santa Monica Mountains, a death cap (Amanita Philloides)
You have to eat it. Touching is not a problem with any mushroom. It doesn't take a lot, but a single mushroom can be your last. The toxin, amatoxin, is neither water not heat soluble, so there is no preparation that makes it other than deadly. The same toxin is in the destroying angel that GirlHiker found. Both are deadly, both can be handled without a worry; done it many time including the death cap I found today
JerryN wrote: ↑You have to eat it. Touching is not a problem with any mushroom. It doesn't take a lot, but a single mushroom can be your last. The toxin, amatoxin, is neither water not heat soluble, so there is no preparation that makes it other than deadly. The same toxin is in the destroying angel that GirlHiker found. Both are deadly, both can be handled without a worry; done it many time including the death cap I found today