# Relationship history for MSHA mine 1201550

Current hierarchy: **Nancy  Hastings → Muncie Sand & Gravel, Inc. → Shick Sand & Gravel**

- 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:** Shick Sand & Gravel → Shick Sand & Gravel; 1950-01-01 to 1986-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Harold R  Shick → Shick Sand & Gravel; 1950-01-01 to 1986-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Harold R  Shick → Shick Sand & Gravel; 1950-01-01 to 1986-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Muncie Sand & Gravel, Inc. → Shick Sand & Gravel; 1986-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hood William E → Shick Sand & Gravel; 1986-07-01 to 2003-05-28; source msha-controller-operator-history
- **controller_controls_operator:** Hood William E → Muncie Sand & Gravel, Inc.; 1986-07-01 to 2003-05-28; source msha-controller-operator-history
- **controller_controls_mine:** Nancy  Hastings → Shick Sand & Gravel; 2003-05-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nancy  Hastings → Muncie Sand & Gravel, Inc.; 2003-05-29 to current/open; source msha-controller-operator-history