# Relationship history for MSHA mine 0901122

Current hierarchy: **David C  Powell → Still Waters Sand & Gravel Inc → BUCHANAN MINE**

- 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:** Sand Man Inc → BUCHANAN MINE; 1999-11-01 to 2001-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Roger H  West → BUCHANAN MINE; 1999-11-01 to 2001-09-17; source msha-controller-operator-history
- **controller_controls_operator:** Roger H  West → Sand Man Inc; 1999-11-01 to 2001-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Still Waters Sand & Gravel Inc → BUCHANAN MINE; 2001-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David C  Powell → BUCHANAN MINE; 2001-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David C  Powell → Still Waters Sand & Gravel Inc; 2001-09-18 to current/open; source msha-controller-operator-history