# Relationship history for MSHA mine 3606217

Current hierarchy: **Shaw Raymond D Jr → Strongarm Coal Company Inc → Strongarm Strip**

- 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:** Strongarm Coal Company Inc → Strongarm Strip; 1976-09-01 to 1977-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Rocco Carmen A Jr → Strongarm Strip; 1976-09-01 to 1977-03-14; source msha-controller-operator-history
- **controller_controls_operator:** Rocco Carmen A Jr → Strongarm Coal Company Inc; 1976-09-01 to 1977-03-14; source msha-controller-operator-history
- **operator_operates_mine:** Strongarm Coal Company Inc → Strongarm Strip; 1977-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Shaw Raymond D Jr → Strongarm Strip; 1977-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shaw Raymond D Jr → Strongarm Coal Company Inc; 1977-03-15 to current/open; source msha-controller-operator-history