# Relationship history for MSHA mine 0404340

Current hierarchy: **Mark  Schipper; Peter  Schipper → Evergreen Concrete Inc → San Juan Pit**

- 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:** Evergreen Concrete Inc → San Juan Pit; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Schipper et al → San Juan Pit; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Schipper et al → Evergreen Concrete Inc; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Peter  Schipper et al → Evergreen Concrete Inc; 1979-10-01 to current/open; source msha-controller-operator-history