# Relationship history for MSHA mine 4703251

Current hierarchy: **Steve  Krentz; Ron  Darnick → Cumberland Materials Llc → CUMBERLAND MAT.**

- 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:** Cumberland Materials Llc → CUMBERLAND MAT.; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ron  Darnick  et al → CUMBERLAND MAT.; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ron  Darnick  et al → Cumberland Materials Llc; 2000-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve  Krentz  et al → Cumberland Materials Llc; 2000-09-01 to current/open; source msha-controller-operator-history