# Relationship history for MSHA mine 3605484

Current hierarchy: **Bittner Darrell J → Bittner Coal Company → 1249-1-2**

- 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:** Bittner Coal Company → 1249-1-2; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bittner Darrell J → 1249-1-2; 1975-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bittner Darrell J → Bittner Coal Company; 1975-01-01 to current/open; source msha-controller-operator-history