# Relationship history for MSHA mine 1515810

Current hierarchy: **Denniston Dallas → Dumas Coal Company Inc → Zachariah #1**

- 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

- **controller_controls_mine:** Denniston Dallas → Zachariah #1; 1983-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dumas Coal Company Inc → Zachariah #1; 1986-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Denniston Dallas → Dumas Coal Company Inc; 1986-01-01 to current/open; source msha-controller-operator-history