# Relationship history for MSHA mine 0102607

Current hierarchy: **Webb Martin B → Rock City Coal & Equipment Inc → Dolin Mine**

- 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:** Webb Martin B → Dolin Mine; 1983-10-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rock City Coal & Equipment Inc → Dolin Mine; 1984-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Webb Martin B → Rock City Coal & Equipment Inc; 1984-10-01 to current/open; source msha-controller-operator-history