# Relationship history for MSHA mine 1601514

Current hierarchy: **Michael Dwain  Bubrig; Brian  Bubrig → Nairn Enterprises Inc. → Nairn Sand 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:** Nairn Enterprises Inc → Nairn Sand Pit; 2011-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael Dwain  Bubrig et al → Nairn Sand Pit; 2011-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael Dwain  Bubrig et al → Nairn Enterprises Inc; 2011-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Bubrig et al → Nairn Enterprises Inc; 2011-04-27 to current/open; source msha-controller-operator-history