# Relationship history for MSHA mine 4603884

Current hierarchy: **Crook Norman E → No Coal Inc → No 236 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Pittston Company → No 236 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Amigo Smokeless Coal Company → No 236 Mine; 1973-01-01 to 1979-01-25; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Amigo Smokeless Coal Company; 1973-01-01 to 1979-01-25; source msha-controller-operator-history
- **operator_operates_mine:** No Coal Inc → No 236 Mine; 1979-01-26 to 1979-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Creska Lucille → No 236 Mine; 1979-01-26 to 1979-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Creska Lucille → No Coal Inc; 1979-01-26 to 1979-04-02; source msha-controller-operator-history
- **operator_operates_mine:** No Coal Inc → No 236 Mine; 1979-04-03 to 1980-02-19; source msha-controller-operator-history
- **controller_controls_mine:** Green Warren → No 236 Mine; 1979-04-03 to 1980-02-19; source msha-controller-operator-history
- **controller_controls_operator:** Green Warren → No Coal Inc; 1979-04-03 to 1980-02-19; source msha-controller-operator-history
- **operator_operates_mine:** No Coal Inc → No 236 Mine; 1980-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crook Norman E → No 236 Mine; 1980-02-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crook Norman E → No Coal Inc; 1980-02-20 to current/open; source msha-controller-operator-history