# Relationship history for MSHA mine 0100264

Current hierarchy: **Franklin William M → B & D Coal Company → #4 Mine (Ug)**

- 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:** Franklin William M → #4 Mine (Ug); 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Gray Coal Company → #4 Mine (Ug); 1950-01-01 to 1972-02-15; source msha-controller-operator-history
- **controller_controls_mine:** Gray Donald L → #4 Mine (Ug); 1950-01-01 to 1972-02-15; source msha-controller-operator-history
- **controller_controls_operator:** Gray Donald L → Gray Coal Company; 1950-01-01 to 1972-02-15; source msha-controller-operator-history
- **operator_operates_mine:** B & D Coal Company → #4 Mine (Ug); 1972-02-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Franklin William M → B & D Coal Company; 1972-02-16 to current/open; source msha-controller-operator-history