# Relationship history for MSHA mine 1514797

Current hierarchy: **Gambrel Glen-David Chittum → Glen Mining Company → No 2 Mine**

- 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:** Helton Beve Et Al → No 2 Mine; 1984-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D & L Coal Company → No 2 Mine; 1984-08-01 to 1984-09-26; source msha-controller-operator-history
- **controller_controls_mine:** Gray Donald Et Al → No 2 Mine; 1984-08-01 to 1984-09-26; source msha-controller-operator-history
- **controller_controls_operator:** Gray Donald Et Al → D & L Coal Company; 1984-08-01 to 1984-09-26; source msha-controller-operator-history
- **operator_operates_mine:** J & B Mining → No 2 Mine; 1984-09-27 to 1986-03-10; source msha-controller-operator-history
- **controller_controls_operator:** Helton Beve Et Al → J & B Mining; 1984-09-27 to 1986-03-10; source msha-controller-operator-history
- **operator_operates_mine:** Glen Mining Company → No 2 Mine; 1986-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gambrel Glen-David Chittum Et Al → No 2 Mine; 1986-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gambrel Glen-David Chittum Et Al → Glen Mining Company; 1986-03-11 to current/open; source msha-controller-operator-history