# Relationship history for MSHA mine 1701191

Current hierarchy: **Andrew  Nickerson; Duane  Nickerson → Nickerson Construction Inc. → Emerson 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Nickerson Construction Inc. → Emerson Pit; 2026-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Andrew  Nickerson et al → Emerson Pit; 2026-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Andrew  Nickerson et al → Nickerson Construction Inc.; 2026-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duane  Nickerson et al → Nickerson Construction Inc.; 2026-05-15 to current/open; source msha-controller-operator-history