# Relationship history for MSHA mine 4001809

Current hierarchy: **Marlow Leonard B → M & M Coal Company → No 1**

- 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:** Glandon Brothers Coal Company → No 1; 1975-02-01 to 1977-05-12; source msha-controller-operator-history
- **controller_controls_mine:** Glandon Walter & Darrell → No 1; 1975-02-01 to 1977-05-12; source msha-controller-operator-history
- **controller_controls_operator:** Glandon Walter & Darrell → Glandon Brothers Coal Company; 1975-02-01 to 1977-05-12; source msha-controller-operator-history
- **operator_operates_mine:** L C King Coal Company → No 1; 1977-05-13 to 1977-10-25; source msha-controller-operator-history
- **controller_controls_mine:** King L C & Bruce → No 1; 1977-05-13 to 1977-10-25; source msha-controller-operator-history
- **controller_controls_operator:** King L C & Bruce → L C King Coal Company; 1977-05-13 to 1977-10-25; source msha-controller-operator-history
- **operator_operates_mine:** M & M Coal Company → No 1; 1977-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marlow Leonard B → No 1; 1977-10-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marlow Leonard B → M & M Coal Company; 1977-10-26 to current/open; source msha-controller-operator-history