# Relationship history for MSHA mine 4503453

Current hierarchy: **Kevin  Tapani; Leigh  Tapani → Tower Rock Products Inc. → Tower Rock**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** John D  Friend et al → Tower Rock; 1950-01-01 to 2006-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Rognlin'S Inc → Tower Rock; 2000-10-01 to 2002-10-22; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin → Tower Rock; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin → Rognlin'S Inc; 2000-10-01 to 2002-10-22; source msha-controller-operator-history
- **operator_operates_mine:** Northwest Rock Incorporated → Tower Rock; 2002-10-23 to 2005-08-11; source msha-controller-operator-history
- **controller_controls_operator:** John D  Friend et al → Northwest Rock Incorporated; 2002-10-23 to 2005-08-11; source msha-controller-operator-history
- **operator_operates_mine:** Tower Rock Products Inc. → Tower Rock; 2005-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kevin  Tapani et al → Tower Rock; 2005-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kevin  Tapani et al → Tower Rock Products Inc.; 2005-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leigh  Tapani et al → Tower Rock Products Inc.; 2005-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Randy  Rognlin → Tower Rock; 2006-03-01 to 2017-12-28; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin → Northwest Rock Incorporated; 2006-03-01 to 2005-08-11; source msha-controller-operator-history
- **controller_controls_mine:** Jason  Messmer et al → Tower Rock; 2017-12-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason  Messmer et al → Northwest Rock Incorporated; 2017-12-29 to 2005-08-11; source msha-controller-operator-history
- **controller_controls_operator:** Randy  Rognlin et al → Northwest Rock Incorporated; 2017-12-29 to 2005-08-11; source msha-controller-operator-history