# Relationship history for MSHA mine 4403475

Current hierarchy: **Pittston Company → Paramont Coal Corp → Deep Mine #21-A**

- 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:** Three D Coal Corp → Deep Mine #21-A; 1950-01-01 to 1980-09-18; source msha-controller-operator-history
- **controller_controls_mine:** Donald  Nicewonder → Deep Mine #21-A; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald  Nicewonder → Three D Coal Corp; 1950-01-01 to 1980-09-18; source msha-controller-operator-history
- **controller_controls_mine:** Mullins Alcieberry → Deep Mine #21-A; 1976-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mountain Fuel Coal Company → Deep Mine #21-A; 1980-09-19 to 1998-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Mullins Alcieberry → Mountain Fuel Coal Company; 1980-09-19 to 1998-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Pittston Company → Deep Mine #21-A; 1986-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Paramont Coal Corp → Deep Mine #21-A; 1998-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pittston Company → Paramont Coal Corp; 1998-06-15 to current/open; source msha-controller-operator-history