# Relationship history for MSHA mine 1507438

Current hierarchy: **Mc Menamy Bernard → R & R Coal Company → No 1 Strip**

- 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

- **operator_operates_mine:** R & R Coal Company → No 1 Strip; 1974-09-01 to 1977-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Reed Ronald → No 1 Strip; 1974-09-01 to 1977-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Reed Ronald → R & R Coal Company; 1974-09-01 to 1977-08-22; source msha-controller-operator-history
- **operator_operates_mine:** R & R Coal Company → No 1 Strip; 1977-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Menamy Bernard → No 1 Strip; 1977-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Menamy Bernard → R & R Coal Company; 1977-08-23 to current/open; source msha-controller-operator-history