# Relationship history for MSHA mine 1508919

Current hierarchy: **Great Western Resources Inc → Great Western Coal Inc → Dulcimer 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Hubbs Joe → Dulcimer No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bow Valley Industries Ltd → Dulcimer No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Austin Bill & W C Forrester → Dulcimer No 1; 1975-04-01 to 1977-08-09; source msha-controller-operator-history
- **operator_operates_mine:** B & C Coal Company → Dulcimer No 1; 1975-12-09 to 1977-08-09; source msha-controller-operator-history
- **controller_controls_operator:** Austin Bill & W C Forrester → B & C Coal Company; 1975-12-09 to 1977-08-09; source msha-controller-operator-history
- **operator_operates_mine:** J & D Coal Company Inc → Dulcimer No 1; 1977-08-10 to 1981-03-02; source msha-controller-operator-history
- **controller_controls_operator:** Hubbs Joe → J & D Coal Company Inc; 1977-08-10 to 1981-03-02; source msha-controller-operator-history
- **operator_operates_mine:** Bow Valley Coal Resources Inc → Dulcimer No 1; 1981-03-03 to 1987-02-03; source msha-controller-operator-history
- **controller_controls_operator:** Bow Valley Industries Ltd → Bow Valley Coal Resources Inc; 1981-03-03 to 1987-02-03; source msha-controller-operator-history
- **operator_operates_mine:** Great Western Coal Inc → Dulcimer No 1; 1987-02-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Great Western Resources Inc → Dulcimer No 1; 1987-02-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Great Western Resources Inc → Great Western Coal Inc; 1987-02-04 to current/open; source msha-controller-operator-history