# Relationship history for MSHA mine 4404949

Current hierarchy: **Barton Lendon → C B S Coal Company → No 1 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:** Darrell L  Boyd → No 1 Mine; 1974-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Double D Coal Company Inc → No 1 Mine; 1978-02-01 to 1978-04-18; source msha-controller-operator-history
- **controller_controls_operator:** Darrell L  Boyd → Double D Coal Company Inc; 1978-02-01 to 1978-04-18; source msha-controller-operator-history
- **operator_operates_mine:** C B S Coal Company → No 1 Mine; 1978-04-19 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Compton William → No 1 Mine; 1978-04-19 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Compton William → C B S Coal Company; 1978-04-19 to 1981-03-25; source msha-controller-operator-history
- **operator_operates_mine:** C B S Coal Company → No 1 Mine; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Barton Lendon → No 1 Mine; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barton Lendon → C B S Coal Company; 1981-03-26 to current/open; source msha-controller-operator-history