# Relationship history for MSHA mine 3609636

Current hierarchy: **Daniel E  Johnson; Donald E  Johnson Jr → Johnson Bros Quarries → Spencer Quarry**

- 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:** Daniel E  Johnson et al → Spencer Quarry; 2004-03-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Bros Quarries → Spencer Quarry; 2008-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel E  Johnson et al → Johnson Bros Quarries; 2008-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald E  Johnson Jr et al → Johnson Bros Quarries; 2008-07-01 to current/open; source msha-controller-operator-history