# Relationship history for MSHA mine 4405475

Current hierarchy: **Steffey Ronnie G → C D F Coal Company Inc → 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:** Boyd Darrell & Fred Sullivan → No 2 Mine; 1977-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C D F Coal Company Inc → No 2 Mine; 1980-08-01 to 1980-08-20; source msha-controller-operator-history
- **controller_controls_mine:** Farmer Cleason D → No 2 Mine; 1980-08-01 to 1980-08-20; source msha-controller-operator-history
- **controller_controls_operator:** Farmer Cleason D → C D F Coal Company Inc; 1980-08-01 to 1980-08-20; source msha-controller-operator-history
- **operator_operates_mine:** C D F Coal Company Inc → No 2 Mine; 1980-08-21 to 1980-11-09; source msha-controller-operator-history
- **controller_controls_operator:** Boyd Darrell & Fred Sullivan → C D F Coal Company Inc; 1980-08-21 to 1980-11-09; source msha-controller-operator-history
- **operator_operates_mine:** C D F Coal Company Inc → No 2 Mine; 1980-11-10 to 1981-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Wilson Donald → No 2 Mine; 1980-11-10 to 1981-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Wilson Donald → C D F Coal Company Inc; 1980-11-10 to 1981-09-30; source msha-controller-operator-history
- **operator_operates_mine:** C D F Coal Company Inc → No 2 Mine; 1981-10-01 to 1984-04-03; source msha-controller-operator-history
- **controller_controls_mine:** Boyd Darrell & Larry Acres → No 2 Mine; 1981-10-01 to 1984-04-03; source msha-controller-operator-history
- **controller_controls_operator:** Boyd Darrell & Larry Acres → C D F Coal Company Inc; 1981-10-01 to 1984-04-03; source msha-controller-operator-history
- **operator_operates_mine:** C D F Coal Company Inc → No 2 Mine; 1984-04-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steffey Ronnie G Et Al → No 2 Mine; 1984-04-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steffey Ronnie G Et Al → C D F Coal Company Inc; 1984-04-04 to current/open; source msha-controller-operator-history