# Relationship history for MSHA mine 4801158

Current hierarchy: **Kerr-McGee Corp → Kerr-Mc Gee Nuclear Corp → Open Pit Sections (28-33)(3-10)**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Kerr-McGee Corp → Open Pit Sections (28-33)(3-10); 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Brothers Company → Open Pit Sections (28-33)(3-10); 1950-01-01 to 1978-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Brothers Company → Open Pit Sections (28-33)(3-10); 1950-01-01 to 1978-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Brothers Company → Johnson Brothers Company; 1950-01-01 to 1978-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Kerr-Mc Gee Nuclear Corp → Open Pit Sections (28-33)(3-10); 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kerr-McGee Corp → Kerr-Mc Gee Nuclear Corp; 1978-09-01 to current/open; source msha-controller-operator-history