# Relationship history for MSHA mine 3101503

Current hierarchy: **Donna R Miller; Larry W Hammill; Ruth H Hammill → Hammill Construction Company Inc → Hammill 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:** Hammill Construction Company Inc → Hammill Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jerry F  Hammill et al → Hammill Pit; 1950-01-01 to 2022-05-03; source msha-controller-operator-history
- **controller_controls_operator:** Jerry F  Hammill et al → Hammill Construction Company Inc; 1950-01-01 to 2022-05-03; source msha-controller-operator-history
- **controller_controls_mine:** Ruth H Hammill et al → Hammill Pit; 2022-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ruth H Hammill et al → Hammill Construction Company Inc; 2022-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Larry W Hammill et al → Hammill Construction Company Inc; 2022-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donna R Miller et al → Hammill Construction Company Inc; 2022-05-04 to current/open; source msha-controller-operator-history