# Relationship history for MSHA mine 0202043

Current hierarchy: **John  Weik → Sun Valley Mining Company → Portable Crusher No. 0033**

- 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:** William A  Walker → Portable Crusher No. 0033; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sun Valley Crushing Company → Portable Crusher No. 0033; 1981-06-01 to 1986-02-28; source msha-controller-operator-history
- **controller_controls_operator:** William A  Walker → Sun Valley Crushing Company; 1981-06-01 to 1986-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Sun Valley Mining Company → Portable Crusher No. 0033; 1986-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John  Weik → Portable Crusher No. 0033; 1986-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Weik → Sun Valley Mining Company; 1986-03-01 to current/open; source msha-controller-operator-history