# Relationship history for MSHA mine 4502535

Current hierarchy: **Grant County - Wa → Grant County Dept Of Public Works → Blanchett Quarry Site**

- 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

- **controller_controls_mine:** James O  Hutchinson  et al → Blanchett Quarry Site; 1950-01-01 to 2023-07-30; source msha-controller-operator-history
- **controller_controls_mine:** Grant County - Wa → Blanchett Quarry Site; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ellensburg Cement Products Inc → Blanchett Quarry Site; 1978-03-09 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_operator:** James O  Hutchinson  et al → Ellensburg Cement Products Inc; 1978-03-09 to 1978-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Grant County Dept Of Public Works → Blanchett Quarry Site; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grant County - Wa → Grant County Dept Of Public Works; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James  Hutchinson → Blanchett Quarry Site; 2023-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Hutchinson → Ellensburg Cement Products Inc; 2023-07-31 to 1978-12-31; source msha-controller-operator-history