# Relationship history for MSHA mine 4703276

Current hierarchy: **Milton D  Ostermann → Glacier Rock Inc → SPOONER 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:** Glacier Rock Inc → SPOONER PIT; 2001-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Milton D  Ostermann → SPOONER PIT; 2001-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Milton D  Ostermann → Glacier Rock Inc; 2001-06-01 to current/open; source msha-controller-operator-history