# Relationship history for MSHA mine 3200685

Current hierarchy: **Abrasives Inc. → Abrasives Inc → Abrasives Inc**

- 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:** Dakota Silica Inc → Abrasives Inc; 1984-08-01 to 1990-05-07; source msha-controller-operator-history
- **controller_controls_mine:** Larry R  Roth → Abrasives Inc; 1984-08-01 to 1990-05-07; source msha-controller-operator-history
- **controller_controls_operator:** Larry R  Roth → Dakota Silica Inc; 1984-08-01 to 1990-05-07; source msha-controller-operator-history
- **operator_operates_mine:** Abrasives Inc → Abrasives Inc; 1990-05-08 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Kyle  Mundstock → Abrasives Inc; 1990-05-08 to 1999-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Kyle  Mundstock → Abrasives Inc; 1990-05-08 to 1999-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Abrasives Inc → Abrasives Inc; 1999-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Larry R  Roth → Abrasives Inc; 1999-04-01 to 2012-01-12; source msha-controller-operator-history
- **controller_controls_operator:** Larry R  Roth → Abrasives Inc; 1999-04-01 to 2012-01-12; source msha-controller-operator-history
- **controller_controls_mine:** Abrasives Inc. → Abrasives Inc; 2012-01-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Abrasives Inc. → Abrasives Inc; 2012-01-13 to current/open; source msha-controller-operator-history