# Relationship history for MSHA mine 4401873

Current hierarchy: **Florida Progress Corporation → Powell Mountain Coal Company Inc → Upper Mason No 2**

- 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:** Smitty Baker Coal Company Inc → Upper Mason No 2; 1950-01-01 to 1986-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Baker Ralph → Upper Mason No 2; 1950-01-01 to 1986-05-21; source msha-controller-operator-history
- **controller_controls_operator:** Baker Ralph → Smitty Baker Coal Company Inc; 1950-01-01 to 1986-05-21; source msha-controller-operator-history
- **controller_controls_mine:** Amvest Corporation → Upper Mason No 2; 1981-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Powell Mountain Coal Company Inc → Upper Mason No 2; 1986-05-22 to 1987-12-02; source msha-controller-operator-history
- **controller_controls_operator:** Amvest Corporation → Powell Mountain Coal Company Inc; 1986-05-22 to 1987-12-02; source msha-controller-operator-history
- **operator_operates_mine:** N O W Coal Company Inc → Upper Mason No 2; 1987-12-03 to 1993-01-28; source msha-controller-operator-history
- **controller_controls_mine:** West James G → Upper Mason No 2; 1987-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** West James G → N O W Coal Company Inc; 1987-12-03 to 1993-01-28; source msha-controller-operator-history
- **operator_operates_mine:** S C M Company Inc → Upper Mason No 2; 1993-01-29 to 1993-08-26; source msha-controller-operator-history
- **controller_controls_mine:** Sturgill Leonard → Upper Mason No 2; 1993-01-29 to 1993-08-26; source msha-controller-operator-history
- **controller_controls_operator:** Sturgill Leonard → S C M Company Inc; 1993-01-29 to 1993-08-26; source msha-controller-operator-history
- **operator_operates_mine:** A & A Mining Inc → Upper Mason No 2; 1993-08-27 to 1997-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Dowdy Edward L Jr → Upper Mason No 2; 1993-08-27 to 1997-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Dowdy Edward L Jr → A & A Mining Inc; 1993-08-27 to 1997-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Florida Progress Corporation → Upper Mason No 2; 1997-09-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Powell Mountain Coal Company Inc → Upper Mason No 2; 1997-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Florida Progress Corporation → Powell Mountain Coal Company Inc; 1997-11-01 to current/open; source msha-controller-operator-history