# Relationship history for MSHA mine 4604975

Current hierarchy: **Billings J H → Delta Minerals Inc → Delta Prep Plant No 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

- **operator_operates_mine:** A B Rose Inc → Delta Prep Plant No 1; 1975-12-01 to 1977-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Rose A B → Delta Prep Plant No 1; 1975-12-01 to 1977-01-26; source msha-controller-operator-history
- **controller_controls_operator:** Rose A B → A B Rose Inc; 1975-12-01 to 1977-01-26; source msha-controller-operator-history
- **controller_controls_mine:** Grubb Ned → Delta Prep Plant No 1; 1977-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Warrior Mining Corp → Delta Prep Plant No 1; 1977-01-27 to 1980-06-18; source msha-controller-operator-history
- **controller_controls_operator:** Grubb Ned → Warrior Mining Corp; 1977-01-27 to 1980-06-18; source msha-controller-operator-history
- **operator_operates_mine:** Pocahontas Coal & Coke Company Inc → Delta Prep Plant No 1; 1980-06-19 to 1980-11-23; source msha-controller-operator-history
- **controller_controls_mine:** Robert R  Bowling → Delta Prep Plant No 1; 1980-06-19 to 1980-11-23; source msha-controller-operator-history
- **controller_controls_operator:** Robert R  Bowling → Pocahontas Coal & Coke Company Inc; 1980-06-19 to 1980-11-23; source msha-controller-operator-history
- **operator_operates_mine:** Delta Minerals Inc → Delta Prep Plant No 1; 1980-11-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Billings J H → Delta Prep Plant No 1; 1980-11-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Billings J H → Delta Minerals Inc; 1980-11-24 to current/open; source msha-controller-operator-history