# Relationship history for MSHA mine 3609694

Current hierarchy: **Donald R.  Gearhart → Penn Development Services, L.P. → Mather Strip**

- 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:** Penn Development Services, L.P. → Mather Strip; 2009-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald R.  Gearhart et al → Mather Strip; 2009-01-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald R.  Gearhart et al → Penn Development Services, L.P.; 2009-01-07 to current/open; source msha-controller-operator-history