# Relationship history for MSHA mine 0503496

Current hierarchy: **Arabian Shield Development Company → American Shield Coal Company → Fruita #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Damson Oil Corp → Fruita #2; 1978-07-01 to 1987-02-06; source msha-controller-operator-history
- **operator_operates_mine:** Dorchester Coal Company → Fruita #2; 1979-10-01 to 1987-02-06; source msha-controller-operator-history
- **controller_controls_operator:** Damson Oil Corp → Dorchester Coal Company; 1979-10-01 to 1987-02-06; source msha-controller-operator-history
- **operator_operates_mine:** American Shield Coal Company → Fruita #2; 1987-02-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Arabian Shield Development Company → Fruita #2; 1987-02-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arabian Shield Development Company → American Shield Coal Company; 1987-02-07 to current/open; source msha-controller-operator-history