# Relationship history for MSHA mine 0504559

Current hierarchy: **Summit Materials LLC → Elam Construction Inc → CEDAR RAPIDS PLANT #3**

- 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 → CEDAR RAPIDS PLANT #3; 1950-01-01 to 2011-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Elam Construction Inc → CEDAR RAPIDS PLANT #3; 1995-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold  Elam → Elam Construction Inc; 1995-04-01 to 2011-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → CEDAR RAPIDS PLANT #3; 2011-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → Elam Construction Inc; 2011-04-01 to current/open; source msha-controller-operator-history