# Relationship history for MSHA mine 5100120

Current hierarchy: **Knife River Corporation → Hawaiian Cement → Waikapu Pit And Mill**

- 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

- **operator_operates_mine:** Maui Concrete & Aggregates Inc → Waikapu Pit And Mill; 1950-01-01 to 1988-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Amelco Corp → Waikapu Pit And Mill; 1950-01-01 to 1993-02-03; source msha-controller-operator-history
- **controller_controls_operator:** Amelco Corp → Maui Concrete & Aggregates Inc; 1950-01-01 to 1988-01-31; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Waikapu Pit And Mill; 1985-10-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Hawaiian Cement → Waikapu Pit And Mill; 1988-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Hawaiian Cement; 1988-02-01 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Waikapu Pit And Mill; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Hawaiian Cement; 2023-06-01 to current/open; source msha-controller-operator-history