(34' x 20', IA-57-09) E. of Robins, Marion Township, Linn County, IA. Mentzer Rd. N. 0.45 miles from jct with Main St. on the E. side of Robins, E. on Knoll Dr. (becomes Echo Hill Rd.) 1.3 miles to the crib on the S. side of the road at 2751. (N42 04.550 W91 38.009) Photo by Jack & June Schmidt 6-19-12.