Marietta Sand Prairie is a 17-acre preserve featuring aeolian (windblown) sand deposits and a sand prairie. It is located seven miles northwest of Marshalltown in Marshall County. The area was purchased in 1983 from the Conrad family by a lifelong Marshall County resident who wanted to give a lasting gift to the county. The prairie, initially named “Conrad Sand Prairie,” was renamed “Marietta Sand Prairie” after the township in which it is located. The area was dedicated as a biological and geological state preserve in 1984.