# Relationship history for MSHA mine 1508185

Current hierarchy: **Runyon Bradford → Guardian Coal Company Inc → 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:** Mc Mullen Enterprises → Prep Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Runyon Bradford → Prep Plant; 1974-11-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A G P Coal Co Inc → Prep Plant; 1975-03-31 to 1977-02-13; source msha-controller-operator-history
- **controller_controls_operator:** Mc Mullen Enterprises → A G P Coal Co Inc; 1975-03-31 to 1977-02-13; source msha-controller-operator-history
- **operator_operates_mine:** Guardian Coal Company Inc → Prep Plant; 1977-02-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Runyon Bradford → Guardian Coal Company Inc; 1977-02-14 to current/open; source msha-controller-operator-history