# Relationship history for MSHA mine 1511556

Current hierarchy: **Dringenburg Harold → Boone Corp → No 1 Prep Plant**

- 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:** Meade James & Edward Slone → No 1 Prep Plant; 1977-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Magna Processing Inc → No 1 Prep Plant; 1978-09-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Berry Odell → No 1 Prep Plant; 1978-09-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Berry Odell → Magna Processing Inc; 1978-09-01 to 1979-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Skyline Coals Inc → No 1 Prep Plant; 1979-12-01 to 1981-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Meade James & Edward Slone → Skyline Coals Inc; 1979-12-01 to 1981-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Boone Corp → No 1 Prep Plant; 1981-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dringenburg Harold → No 1 Prep Plant; 1981-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dringenburg Harold → Boone Corp; 1981-04-01 to current/open; source msha-controller-operator-history