# Relationship history for MSHA mine 4604205

Current hierarchy: **Monk Bill → M & L Coal Company Inc → 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

- **controller_controls_mine:** B & F Coal Company → No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & F Coal Company → No 1; 1974-06-24 to 1976-07-06; source msha-controller-operator-history
- **controller_controls_operator:** B & F Coal Company → B & F Coal Company; 1974-06-24 to 1976-07-06; source msha-controller-operator-history
- **operator_operates_mine:** Economy Fuel Coal Company → No 1; 1976-07-07 to 1980-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Cline Erma → No 1; 1976-07-07 to 1980-05-06; source msha-controller-operator-history
- **controller_controls_operator:** Cline Erma → Economy Fuel Coal Company; 1976-07-07 to 1980-05-06; source msha-controller-operator-history
- **operator_operates_mine:** Economy Fuel Coal Company → No 1; 1980-05-07 to 1987-03-26; source msha-controller-operator-history
- **controller_controls_mine:** Sparks Donald J & Ariland Steele → No 1; 1980-05-07 to 1987-03-26; source msha-controller-operator-history
- **controller_controls_operator:** Sparks Donald J & Ariland Steele → Economy Fuel Coal Company; 1980-05-07 to 1987-03-26; source msha-controller-operator-history
- **operator_operates_mine:** M & L Coal Company Inc → No 1; 1987-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Monk Bill → No 1; 1987-03-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Monk Bill → M & L Coal Company Inc; 1987-03-27 to current/open; source msha-controller-operator-history