# Relationship history for MSHA mine 4201479

Current hierarchy: **Summit Materials LLC → Kilgore Contracting → Erda Pit**

- 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:** Harold  Elam → Erda Pit; 1950-01-01 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** S Val  Staker → Erda Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Staker Paving & Construction Company Inc → Erda Pit; 1978-03-09 to 1992-08-23; source msha-controller-operator-history
- **controller_controls_operator:** S Val  Staker → Staker Paving & Construction Company Inc; 1978-03-09 to 1992-08-23; source msha-controller-operator-history
- **controller_controls_mine:** Harper Investments Inc → Erda Pit; 1978-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Harper Sand & Gravel → Erda Pit; 1992-08-24 to 2010-08-01; source msha-controller-operator-history
- **controller_controls_operator:** Harper Investments Inc → Harper Sand & Gravel; 1992-08-24 to 2010-08-01; source msha-controller-operator-history
- **operator_operates_mine:** Kilgore Contracting → Erda Pit; 2010-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold  Elam → Kilgore Contracting; 2010-08-02 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Erda Pit; 2011-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Kilgore Contracting; 2011-04-01 to current/open; source msha-controller-operator-history