# Relationship history for MSHA mine 2800969

Current hierarchy: **Morrison Knudsen Corp (Old) → Lime Crest Mining Company → Lime Crest Quarry**

- 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:** Lime Crest Mining Company → Lime Crest Quarry; 1984-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Morrison Knudsen Corp (Old) → Lime Crest Quarry; 1984-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Morrison Knudsen Corp (Old) → Lime Crest Mining Company; 1984-11-01 to current/open; source msha-controller-operator-history