# Relationship history for MSHA mine 2002908

Current hierarchy: **Genoak Materials Inc → Tri-City Aggregates Inc → Portable NDA**

- 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:** Genoak Materials Inc → Portable NDA; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Construction Materials Inc → Portable NDA; 1993-09-01 to 2001-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Dave  Cutler → Portable NDA; 1993-09-01 to 2001-09-17; source msha-controller-operator-history
- **controller_controls_operator:** Dave  Cutler → Construction Materials Inc; 1993-09-01 to 2001-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Tri-City Aggregates Inc → Portable NDA; 2001-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Genoak Materials Inc → Tri-City Aggregates Inc; 2001-09-18 to current/open; source msha-controller-operator-history