# Relationship history for MSHA mine 0102163

Current hierarchy: **Keller Elsie R → Keller Construction Inc → Acmar**

- 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:** Keller Elsie R → Acmar; 1976-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keller Construction Inc → Acmar; 1979-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keller Elsie R → Keller Construction Inc; 1979-12-01 to current/open; source msha-controller-operator-history