# Relationship history for MSHA mine 0201879

Current hierarchy: **Johnson Jim → Johnson Granite → Johnson Granite**

- 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:** Thunderbird Granite Supply → Johnson Granite; 1978-03-09 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Thunderbird Granite Supply → Johnson Granite; 1978-03-09 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Thunderbird Granite Supply → Thunderbird Granite Supply; 1978-03-09 to 1980-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Granite → Johnson Granite; 1980-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Jim → Johnson Granite; 1980-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Jim → Johnson Granite; 1980-03-01 to current/open; source msha-controller-operator-history