# Relationship history for MSHA mine 0202839

Current hierarchy: **Dennis  Mahan → Mahan Sand & Gravel Materials → Mahan Sand & Gravel Materials**

- 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:** Mahan Materials → Mahan Sand & Gravel Materials; 1999-09-01 to 2001-09-05; source msha-controller-operator-history
- **controller_controls_mine:** Lee  Mahan → Mahan Sand & Gravel Materials; 1999-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lee  Mahan → Mahan Materials; 1999-09-01 to 2001-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Mahan Sand & Gravel Materials → Mahan Sand & Gravel Materials; 2001-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis  Mahan → Mahan Sand & Gravel Materials; 2001-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis  Mahan → Mahan Sand & Gravel Materials; 2001-09-06 to current/open; source msha-controller-operator-history