# Relationship history for MSHA mine 4702906

Current hierarchy: **Keith  Bonville → Harbor Construction Of Door County, Inc. → OLDENBURG 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:** Harbor Construction Of Door County Inc → OLDENBURG PIT; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Keith  Bonville → OLDENBURG PIT; 1990-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keith  Bonville → Harbor Construction Of Door County Inc; 1990-06-01 to current/open; source msha-controller-operator-history