# Relationship history for MSHA mine 2901871

Current hierarchy: **Alfonso R  Ulibarri → Ulibarri Landscaping Material Inc → PENA BLANCA PIT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Ulibarri Landscaping Material Inc → PENA BLANCA PIT; 1981-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Alfonso R  Ulibarri → PENA BLANCA PIT; 1981-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alfonso R  Ulibarri → Ulibarri Landscaping Material Inc; 1981-07-01 to current/open; source msha-controller-operator-history