From the PNW Key Council Agaricus key:
CAP 8-11.5 cm broad; white at first, gradually buff to light ochraceous, then pinkish-gray. ODOR slightly unpleasant almond. GILLS white in very young button then grayish pink. STEM 8-11 cm long, 3 cm thick; smooth clavate with slight bulbous base. RING double cogwheel. HABITAT found in open grassy places with moss.