The possible anvilstone has received a great deal of scrutiny. This is a very large stone: 4.5 kg in weight, 21.6 cm long, 15 cm wide, and 12 cm thick. It is much larger than any other stones at this level (Ray 2000:69). Using the Sac River, experiments were conducted to determine if the stone could have been moved to this position by the river. Even during water discharges from the Stockton dam, the stone failed to be moved by the water. Ray and Lopinot have thus concluded that it is most likely a manuport, though other transport methods such as rootwad rafting and ice-rafting can not be entirely ruled out (Chandler 2001b). One other curious feature regarding the stone's location is that the stone is broken into three pieces, situated very close together. One end of the stone is broken off, with a spall from the break. The broken piece is rotated 120 degrees from its original position and would be at a right angle to the flow of the water had its relocation been through water action. In addition, the spall, which is from the upper surface of the stone, is under the smaller piece. This is highly suggestive of the piece being deliberately moved after the break occurred (Ray 2000:69).