# Relationship history for MSHA mine 1301722

Current hierarchy: **Monarch Cement Company → Monarch Cement Company → Des Moines Plant**

- 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

- **operator_operates_mine:** Marquette Cement Manufacturing Company → Des Moines Plant; 1950-01-01 to 1979-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Gulf + Western Industries Inc → Des Moines Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gulf + Western Industries Inc → Marquette Cement Manufacturing Company; 1950-01-01 to 1979-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Monarch Cement Company → Des Moines Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Monarch Cement Company → Des Moines Plant; 1979-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Monarch Cement Company → Monarch Cement Company; 1979-06-01 to current/open; source msha-controller-operator-history