# Relationship history for MSHA mine 3606027

Current hierarchy: **Troup Randy & William Blase → Big Foot Coal Company → No 1 Stripping**

- 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:** Crystal Development Company Inc → No 1 Stripping; 1976-03-22 to 1976-10-27; source msha-controller-operator-history
- **controller_controls_mine:** Thomas J  Lynott → No 1 Stripping; 1976-03-22 to 1976-10-27; source msha-controller-operator-history
- **controller_controls_operator:** Thomas J  Lynott → Crystal Development Company Inc; 1976-03-22 to 1976-10-27; source msha-controller-operator-history
- **operator_operates_mine:** Crystal Development Company Inc → No 1 Stripping; 1976-10-28 to 1979-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Lereah Michael → No 1 Stripping; 1976-10-28 to 1979-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Lereah Michael → Crystal Development Company Inc; 1976-10-28 to 1979-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Columbia Coal & Development Company Inc → No 1 Stripping; 1979-04-03 to 1990-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Thomas J  Lynott → No 1 Stripping; 1979-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas J  Lynott → Columbia Coal & Development Company Inc; 1979-04-03 to 1990-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Troup Randy & William Blase → No 1 Stripping; 1988-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Big Foot Coal Company → No 1 Stripping; 1990-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Troup Randy & William Blase → Big Foot Coal Company; 1990-08-07 to current/open; source msha-controller-operator-history