# Relationship history for MSHA mine 1511968

Current hierarchy: **Harold K  Simpson → S & B Coal Company Inc → S & B 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

- **controller_controls_mine:** Woodward Earnest → S & B No 2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Straight Ridge Coal Company → S & B No 2; 1979-07-01 to 1980-03-18; source msha-controller-operator-history
- **controller_controls_operator:** Woodward Earnest → Straight Ridge Coal Company; 1979-07-01 to 1980-03-18; source msha-controller-operator-history
- **operator_operates_mine:** Rim Mining Company → S & B No 2; 1980-03-19 to 1982-08-11; source msha-controller-operator-history
- **controller_controls_mine:** Grande Edvard → S & B No 2; 1980-03-19 to 1982-08-11; source msha-controller-operator-history
- **controller_controls_operator:** Grande Edvard → Rim Mining Company; 1980-03-19 to 1982-08-11; source msha-controller-operator-history
- **controller_controls_mine:** Harold K  Simpson → S & B No 2; 1982-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Misty Valley Coal Company Inc → S & B No 2; 1982-08-12 to 1983-05-11; source msha-controller-operator-history
- **controller_controls_mine:** Fielden Larry C → S & B No 2; 1982-08-12 to 1983-05-11; source msha-controller-operator-history
- **controller_controls_operator:** Fielden Larry C → Misty Valley Coal Company Inc; 1982-08-12 to 1983-05-11; source msha-controller-operator-history
- **operator_operates_mine:** Big Four Coal Company → S & B No 2; 1983-05-12 to 1983-09-06; source msha-controller-operator-history
- **controller_controls_mine:** Lewis Curtis → S & B No 2; 1983-05-12 to 1983-09-06; source msha-controller-operator-history
- **controller_controls_operator:** Lewis Curtis → Big Four Coal Company; 1983-05-12 to 1983-09-06; source msha-controller-operator-history
- **operator_operates_mine:** Big Four Coal Company → S & B No 2; 1983-09-07 to 1983-10-20; source msha-controller-operator-history
- **controller_controls_mine:** Mc Daniel Aster → S & B No 2; 1983-09-07 to 1983-10-20; source msha-controller-operator-history
- **controller_controls_operator:** Mc Daniel Aster → Big Four Coal Company; 1983-09-07 to 1983-10-20; source msha-controller-operator-history
- **operator_operates_mine:** Big Four Coal Company → S & B No 2; 1983-10-21 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_mine:** Crabtree Harvey → S & B No 2; 1983-10-21 to 1985-10-17; source msha-controller-operator-history
- **controller_controls_operator:** Crabtree Harvey → Big Four Coal Company; 1983-10-21 to 1985-10-17; source msha-controller-operator-history
- **operator_operates_mine:** S & B Coal Company Inc → S & B No 2; 1985-10-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold K  Simpson → S & B Coal Company Inc; 1985-10-18 to current/open; source msha-controller-operator-history