# Relationship history for MSHA mine 4000688

Current hierarchy: **Lackey Eugene → Blue Bird Coal Corp → 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

- **operator_operates_mine:** Indian Creek Coal Company Inc → No 2 Mine; 1971-01-01 to 1977-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Indian Creek Coal Company Inc → No 2 Mine; 1971-01-01 to 1977-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Indian Creek Coal Company Inc → Indian Creek Coal Company Inc; 1971-01-01 to 1977-03-09; source msha-controller-operator-history
- **operator_operates_mine:** Petros Coal Company → No 2 Mine; 1977-03-10 to 1978-11-14; source msha-controller-operator-history
- **controller_controls_mine:** Carroll Sherman → No 2 Mine; 1977-03-10 to 1978-11-14; source msha-controller-operator-history
- **controller_controls_operator:** Carroll Sherman → Petros Coal Company; 1977-03-10 to 1978-11-14; source msha-controller-operator-history
- **operator_operates_mine:** Blue Bird Coal Corp → No 2 Mine; 1978-11-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lackey Eugene → No 2 Mine; 1978-11-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lackey Eugene → Blue Bird Coal Corp; 1978-11-15 to current/open; source msha-controller-operator-history