# Relationship history for MSHA mine 3200643

Current hierarchy: **Timothy R  Logan → O H Blumer Construction Inc → BLUMER PIT & PLANT NO 1**

- 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:** O H Blumer Construction Inc → BLUMER PIT & PLANT NO 1; 1980-04-01 to 1983-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Oscar H  Blumer → BLUMER PIT & PLANT NO 1; 1980-04-01 to 1983-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Oscar H  Blumer → O H Blumer Construction Inc; 1980-04-01 to 1983-12-31; source msha-controller-operator-history
- **operator_operates_mine:** O H Blumer Construction Inc → BLUMER PIT & PLANT NO 1; 1984-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Timothy R  Logan → BLUMER PIT & PLANT NO 1; 1984-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Timothy R  Logan → O H Blumer Construction Inc; 1984-01-01 to current/open; source msha-controller-operator-history