# Relationship history for MSHA mine 0800930

Current hierarchy: **Southdown Inc → Florida Mining & Materials Corp → Florida Mining & Materials Corp-Crushing**

- 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:** Moore Mc Cormack Resources Inc → Florida Mining & Materials Corp-Crushing; 1950-01-01 to 1988-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Florida Mining & Materials Corp → Florida Mining & Materials Corp-Crushing; 1979-01-01 to 1988-09-05; source msha-controller-operator-history
- **controller_controls_operator:** Moore Mc Cormack Resources Inc → Florida Mining & Materials Corp; 1979-01-01 to 1988-09-05; source msha-controller-operator-history
- **operator_operates_mine:** Florida Mining & Materials Corp → Florida Mining & Materials Corp-Crushing; 1988-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Southdown Inc → Florida Mining & Materials Corp-Crushing; 1988-09-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Southdown Inc → Florida Mining & Materials Corp; 1988-09-06 to current/open; source msha-controller-operator-history