# Relationship history for MSHA mine 3607403

Current hierarchy: **Hanson Anthony John → Blackwood Anthracite Inc → Blackwood**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Blackwood Anthracite Inc → Blackwood; 1982-12-01 to 1986-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Camm Harry Et Al → Blackwood; 1982-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Camm Harry Et Al → Blackwood Anthracite Inc; 1982-12-01 to 1986-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Blackwood Anthracite Inc → Blackwood; 1986-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson Anthony John → Blackwood; 1986-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson Anthony John → Blackwood Anthracite Inc; 1986-01-14 to current/open; source msha-controller-operator-history