# Relationship history for MSHA mine 0100740

Current hierarchy: **Hardin Donald A → Donald Hardin Construction Company Inc → Forest Service Pit**

- 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:** W S Dickey Clay Manufacturing Company → Forest Service Pit; 1950-01-01 to 1986-04-08; source msha-controller-operator-history
- **controller_controls_mine:** Hepworth Plc → Forest Service Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hepworth Plc → W S Dickey Clay Manufacturing Company; 1950-01-01 to 1986-04-08; source msha-controller-operator-history
- **operator_operates_mine:** Donald Hardin Construction Company Inc → Forest Service Pit; 1986-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hardin Donald A → Forest Service Pit; 1986-04-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hardin Donald A → Donald Hardin Construction Company Inc; 1986-04-09 to current/open; source msha-controller-operator-history