# Relationship history for MSHA mine 3609664

Current hierarchy: **Hannah L  Robinson → H.L.Robinson Sand & Gravel, Inc → Palmer Mine**

- 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:** Hannah L  Robinson → Palmer Mine; 1988-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** ANP Stone → Palmer Mine; 2008-08-27 to 2011-06-29; source msha-controller-operator-history
- **controller_controls_mine:** John P  Palmer → Palmer Mine; 2008-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John P  Palmer → ANP Stone; 2008-08-27 to 2011-06-29; source msha-controller-operator-history
- **operator_operates_mine:** H.L.Robinson Sand & Gravel, Inc → Palmer Mine; 2011-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hannah L  Robinson → H.L.Robinson Sand & Gravel, Inc; 2011-06-30 to current/open; source msha-controller-operator-history