# Relationship history for MSHA mine 4000048

Current hierarchy: **Michael  Hollingshead → SRM Materials → SRM Materials Tri County**

- 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

- **operator_operates_mine:** Tri County Stone Company Inc → SRM Materials Tri County; 1950-01-01 to 2023-12-10; source msha-controller-operator-history
- **controller_controls_mine:** Stanley R  Hitchcock et al → SRM Materials Tri County; 1950-01-01 to 2020-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Stanley R  Hitchcock et al → Tri County Stone Company Inc; 1950-01-01 to 2020-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Hollingshead et al → SRM Materials Tri County; 2013-12-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Waymon H Hale → SRM Materials Tri County; 2020-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Waymon H Hale → Tri County Stone Company Inc; 2020-02-01 to 2023-12-10; source msha-controller-operator-history
- **operator_operates_mine:** SRM Materials → SRM Materials Tri County; 2023-12-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Hollingshead et al → SRM Materials; 2023-12-11 to current/open; source msha-controller-operator-history