# Relationship history for MSHA mine 3608705

Current hierarchy: **Roger A  Thomas; Miriam R  Thomas → RAMM Coal Inc. → Laurel Ridge #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:** Roger A  Thomas et al → Laurel Ridge #1; 1980-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** RAMM Coal Inc. → Laurel Ridge #1; 1997-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger A  Thomas et al → RAMM Coal Inc.; 1997-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Miriam R  Thomas et al → RAMM Coal Inc.; 1997-11-01 to current/open; source msha-controller-operator-history