# Relationship history for MSHA mine 1506813

Current hierarchy: **Fields Mason & Larry Ratliff → L & M Coal Company Inc → No 3 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:** Island Creek Coal Company → No 3 Mine; 1950-01-01 to 1981-02-16; source msha-controller-operator-history
- **controller_controls_mine:** Occidental Petroleum Corp → No 3 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Island Creek Coal Company; 1950-01-01 to 1981-02-16; source msha-controller-operator-history
- **controller_controls_mine:** Fields Mason & Larry Ratliff → No 3 Mine; 1975-11-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** L & M Coal Company Inc → No 3 Mine; 1981-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fields Mason & Larry Ratliff → L & M Coal Company Inc; 1981-02-17 to current/open; source msha-controller-operator-history