# Relationship history for MSHA mine 1600301

Current hierarchy: **Lynn  Evans → Norris Springs Gravel LLC → Aubrey Chisum 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:** A B Chisum Gravel Company → Aubrey Chisum Pit; 1950-01-01 to 2003-03-03; source msha-controller-operator-history
- **controller_controls_mine:** Chisum A B → Aubrey Chisum Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Chisum A B → A B Chisum Gravel Company; 1950-01-01 to 2003-03-03; source msha-controller-operator-history
- **operator_operates_mine:** Norris Springs Gravel LLC → Aubrey Chisum Pit; 2003-03-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lynn  Evans → Aubrey Chisum Pit; 2003-03-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lynn  Evans → Norris Springs Gravel LLC; 2003-03-04 to current/open; source msha-controller-operator-history