A bucket mounted sifter assembly includes a ring that is positionable around a top end of a bucket. A pair of handles is each coupled to the ring for gripping. A first screen is positioned within the ring, and rocks and particulates can be positioned on the first screen. The first screen has openings therein of approximately 0.5 inches in size to facilitate the particulates to fall therethrough while inhibiting the rocks from passing therethrough for sifting the rocks. A second screen is positionable on the first screen and the second screen has openings therein of approximately 0.25 inches in size. Thus, the second screen reduces the size of material that can pass through the second and first screens. A fastener is extendable through the first and second screens when the second screen is positioned on the first screen for releasably coupling the second screen to the first screen.