# Relationship history for MSHA mine 4102878

Current hierarchy: **Stafford Henry L → Henry L Stafford Construction Company → Hockley County Pits-J Clevenger 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Henry L Stafford Construction Company → Hockley County Pits-J Clevenger Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stafford Henry L → Hockley County Pits-J Clevenger Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stafford Henry L → Henry L Stafford Construction Company; 1979-01-01 to current/open; source msha-controller-operator-history