# Relationship history for MSHA mine 1700256

Current hierarchy: **Alton B  McQuade; Graden G  Tidd → Steelstone Industries I → STEELSTONE INDUSTRIES I**

- 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

- **operator_operates_mine:** Steelstone Industries Inc → STEELSTONE INDUSTRIES I; 1950-01-01 to 2006-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Eugene C  Bartley → STEELSTONE INDUSTRIES I; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eugene C  Bartley → Steelstone Industries Inc; 1950-01-01 to 2006-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Steelstone Industries I → STEELSTONE INDUSTRIES I; 2006-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alton B  McQuade et al → STEELSTONE INDUSTRIES I; 2006-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alton B  McQuade et al → Steelstone Industries I; 2006-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Graden G  Tidd et al → Steelstone Industries I; 2006-05-01 to current/open; source msha-controller-operator-history