Thank you all for your suggestions. I really like the mechanical sifter Nanker linked to. Buffalo Bud- that sifter you linked to is similar to the one I used last year. I bought 3 2x4s, split one in half, screwed them together, and nailed hardware cloth inside and sifted soil all summer manually.
The reason I need to use a sifter is my backyard is a gigantic glacier rock facing south. The garden is also landscape architecture. I have been digging the dirt off the rock exposing the stone, and where there are cavities I am planting different gardens and fire pits. It is a massive undertaking that I have spent hundreds of hours on- and I am about 33% from my ultimate goal. I would estimate for every 5 gallons dirt I dig I yield 2 gallons tiny rocks. The tiny rocks I sift out and put on bottom layer for irrigation. The big rocks I dig up I built some temporary walls. My brother is a mason and ultimately we are going to build proper retaining walls with the field stone collected. A mechanical sifter would save me incredible amounts of time, and wear and tear on my body. It will be gorgeous whenever it is completed. I sit atop a hill secluded but high enough for water views and a 360 degree view of the sky. It makes for excellent star viewing