# Relationship history for MSHA mine 2200588

Current hierarchy: **Smith Toxie & Lonnie Bolling → Buck Creek Sand & Gravel → Watkins 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:** Toxie Smith Sand & Gravel → Watkins Pit; 1986-12-01 to 1987-09-02; source msha-controller-operator-history
- **controller_controls_mine:** Smith Toxie → Watkins Pit; 1986-12-01 to 1987-09-02; source msha-controller-operator-history
- **controller_controls_operator:** Smith Toxie → Toxie Smith Sand & Gravel; 1986-12-01 to 1987-09-02; source msha-controller-operator-history
- **operator_operates_mine:** Buck Creek Sand & Gravel → Watkins Pit; 1987-09-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smith Toxie & Lonnie Bolling → Watkins Pit; 1987-09-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Toxie & Lonnie Bolling → Buck Creek Sand & Gravel; 1987-09-03 to current/open; source msha-controller-operator-history