# Relationship history for MSHA mine 1515526

Current hierarchy: **Clyde A  Mullins → Hidden Hollow Energy Corp → 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:** Dark Diamond Inc → No 1; 1985-12-01 to 1987-02-18; source msha-controller-operator-history
- **controller_controls_mine:** Pruett William D → No 1; 1985-12-01 to 1987-02-18; source msha-controller-operator-history
- **controller_controls_operator:** Pruett William D → Dark Diamond Inc; 1985-12-01 to 1987-02-18; source msha-controller-operator-history
- **operator_operates_mine:** Vance Brothers Coal Company → No 1; 1987-02-19 to 1987-03-10; source msha-controller-operator-history
- **controller_controls_mine:** Vance Clell P Et Al → No 1; 1987-02-19 to 1987-03-10; source msha-controller-operator-history
- **controller_controls_operator:** Vance Clell P Et Al → Vance Brothers Coal Company; 1987-02-19 to 1987-03-10; source msha-controller-operator-history
- **operator_operates_mine:** Hidden Hollow Energy Corp → No 1; 1987-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Clyde A  Mullins → No 1; 1987-03-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clyde A  Mullins → Hidden Hollow Energy Corp; 1987-03-11 to current/open; source msha-controller-operator-history