# Relationship history for MSHA mine 1515504

Current hierarchy: **Horton Steve → Ramblin Coal Company Inc → Mine No 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

- **controller_controls_mine:** Horton Steve → Mine No 2; 1983-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ramblin Coal Company Inc → Mine No 2; 1986-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horton Steve → Ramblin Coal Company Inc; 1986-01-01 to current/open; source msha-controller-operator-history