# Relationship history for MSHA mine 1516531

Current hierarchy: **Gregory Tom → Dinosaurus Coal Corp → No 1 Hound Hollow**

- 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:** Dinosaurus Coal Corp → No 1 Hound Hollow; 1988-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gregory Tom → No 1 Hound Hollow; 1988-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory Tom → Dinosaurus Coal Corp; 1988-10-01 to current/open; source msha-controller-operator-history