# Relationship history for MSHA mine 0400357

Current hierarchy: **David R  Butler → Mariposa Yosemite Slate Quarry → Yosemite Slate Quarry**

- 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:** Mariposa Flagstone Company → Yosemite Slate Quarry; 1950-01-01 to 1996-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Fritz H  Grau → Yosemite Slate Quarry; 1950-01-01 to 1996-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Fritz H  Grau → Mariposa Flagstone Company; 1950-01-01 to 1996-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Mariposa Flagstone Company → Yosemite Slate Quarry; 1997-01-01 to 2012-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Ted C  Verceles → Yosemite Slate Quarry; 1997-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ted C  Verceles → Mariposa Flagstone Company; 1997-01-01 to 2012-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Mariposa Yosemite Slate Quarry → Yosemite Slate Quarry; 2012-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David R  Butler → Yosemite Slate Quarry; 2012-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David R  Butler → Mariposa Yosemite Slate Quarry; 2012-06-06 to current/open; source msha-controller-operator-history