These are the parks thicket knows about in O'Brien — the big ones you already know, and the pocket parks, greenways and trailheads two streets over that you probably do not.
- Archer City Park
- Covey Church Park
- Dog Creek County Park
- Douma Park
- Efil Park
- Flinders Area
- Hannibal Waterman Wildlife Area
- Hills Park
- Litka Park
- McCormack Prairie
- Mill Creek State Park
- Mill Creek Wildlife Area
- Miller Park
- Neebel Park
- Negus Recreation Area
- Northern Tallgrass Prairie National Wildlife Refuge
- Paullina City Park
- Prairie Heritage Center
- Primghar City Park
- Railroad Area
- Schemper Park
- Sheldon City Park
- Shinkle Park
- Sunrise Park
- Swanson Complex
- Thorman Park
- Tjossem Park
- Waterman Creek Wildlife Management Area
- Waterman Prairie Complex
- Waterman Wildlife Addition
- Weafe Wildlife Area
- Williams Wetland
- Wittrock Indian Village State Preserve