In 1984 a group from the Northern Nut Growers Association searched the bottoms on the Mississippi for Pecans, Hicans, and Shellbarks from Bellevue, Iowa to below Clinton, Iowa.  Some of the best and farthest north findings were:

Pleasant Creek…101 Snaps & 125 Deerstand (early Sept. ripe, 1”round &1.5”{long} respectively, papershells), 164 6-Part-Hican (early, 2”, Burlington type),  121 PK Colby (late Sept. ripe, big nut~1.5”, thick hull),  116 Flatrick & 132 Sfoiles (late Sept. ripe, big long nuts~2”, {got no scions 116 due to height}), 102 Jumbo (1.5”but narrow, largest of the mid-Sept. ripe)

Green Island…164, 168 Bank, 184, &199 Diken (mid-Sept. ripe, 1”+, plump), 165 Oaks (early Sept ripe, 1”+, papershell, but pale leaf like Colby variety), 166 Green Island Long (late September, 1.5”+, plump)

Adams Island #8 ( 1”+ round nut, papershell, {never got good scion wood to graft})

Hanson’s Landing Shellbarks (Row of very flat shellbarks {both white and tan shell, could be hybrids with red hickory}, could be commercial due to ease of cracking flat nuts, along the bank of slough opposite Adams Island, no grafts due to too tall trees).