# Relationship history for MSHA mine 4406521

Current hierarchy: **Thyssen Schachtbau Gmbh → Carbomin Corp → Facility No 1**

- 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

- **controller_controls_mine:** Yates Elzie → Facility No 1; 1987-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Continental Colony Corp → Facility No 1; 1989-06-01 to 1990-03-20; source msha-controller-operator-history
- **controller_controls_operator:** Yates Elzie → Continental Colony Corp; 1989-06-01 to 1990-03-20; source msha-controller-operator-history
- **operator_operates_mine:** Carbomin Corp → Facility No 1; 1990-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thyssen Schachtbau Gmbh → Facility No 1; 1990-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thyssen Schachtbau Gmbh → Carbomin Corp; 1990-03-21 to current/open; source msha-controller-operator-history