# Relationship history for MSHA mine 2500286

Current hierarchy: **Ash Grove Cement Company → Hartford Sand & Gravel Company → Mc Cann South Pit #10**

- 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:** Ash Grove Cement Company → Mc Cann South Pit #10; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Don  Rogert → Mc Cann South Pit #10; 1950-01-01 to 1988-02-21; source msha-controller-operator-history
- **operator_operates_mine:** Mc Cann Sand & Gravel Company → Mc Cann South Pit #10; 1950-01-01 to 1979-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Mc Cann Sand & Gravel Company → Mc Cann South Pit #10; 1950-01-01 to 1979-01-24; source msha-controller-operator-history
- **controller_controls_operator:** Mc Cann Sand & Gravel Company → Mc Cann Sand & Gravel Company; 1950-01-01 to 1979-01-24; source msha-controller-operator-history
- **operator_operates_mine:** Hartford Sand & Gravel Company → Mc Cann South Pit #10; 1979-01-25 to 1988-02-21; source msha-controller-operator-history
- **controller_controls_operator:** Don  Rogert → Hartford Sand & Gravel Company; 1979-01-25 to 1988-02-21; source msha-controller-operator-history
- **operator_operates_mine:** Hartford Sand & Gravel Company → Mc Cann South Pit #10; 1988-02-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ash Grove Cement Company → Hartford Sand & Gravel Company; 1988-02-22 to current/open; source msha-controller-operator-history