| 2018 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2017 | Bruce E and Debra K Grewcock Foundation | 990PF | Director | 1 | $0 | $0 | View return |
| 2017 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2016 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2016 | Bruce E and Debra K Grewcock Foundation | 990PF | Director | 1 | $0 | $0 | View return |
| 2016 | Omaha Zoological Society Inc. | 990 | Director | 1 | $0 | $0 | View return |
| 2016 | Nebraska Game and Parks Foundation | 990 | Director | 0 | $0 | $0 | View return |
| 2015 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2015 | Bruce E and Debra K Grewcock Foundation | 990PF | Director | 1 | $0 | $0 | View return |
| 2015 | Nebraska Game and Parks Foundation | 990 | Director | 0 | $0 | $0 | View return |
| 2015 | Omaha Zoo Foundation | 990 | Director | 1 | $0 | $0 | View return |
| 2015 | Omaha Zoological Society Inc. | 990 | Director | 1 | $0 | $0 | View return |
| 2014 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2014 | Nebraska Game and Parks Foundation | 990 | Director | 0 | $0 | $0 | View return |
| 2014 | Omaha Zoological Society Inc. | 990 | Director | 1 | $0 | $0 | View return |
| 2014 | Bruce E and Debra K Grewcock Foundation | 990PF | Director | 1 | $0 | $0 | View return |
| 2013 | Nebraska Game and Parks Foundation | 990 | Director | 0 | $0 | $0 | View return |
| 2013 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2013 | Omaha Zoological Society Inc. | 990 | Director | 1 | $0 | $0 | View return |
| 2012 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2011 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |
| 2010 | Bill and Berniece Grewcock Foundation | 990PF | President/Treasurer/Direct | 1 | $0 | $0 | View return |