# Relationship history for MSHA mine 1516045

Current hierarchy: **Tackett Curtiss → C & N Coal Company → No 16**

- 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:** Tackett Curtiss → No 16; 1974-09-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** C & N Coal Company → No 16; 1987-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tackett Curtiss → C & N Coal Company; 1987-05-01 to current/open; source msha-controller-operator-history