# Relationship history for MSHA mine 3609239

Current hierarchy: **Melvin  Heeman → M & M Flagstone → Ober  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 → Ober  Quarry; 2004-03-17 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Johnson Bros Quarrys → Ober  Quarry; 2004-04-28 to 2008-07-07; source msha-controller-operator-history
- **controller_controls_operator:** Daniel E  Johnson et al → Johnson Bros Quarrys; 2004-04-28 to 2008-07-07; source msha-controller-operator-history
- **controller_controls_operator:** Donald E  Johnson Jr et al → Johnson Bros Quarrys; 2004-04-28 to 2008-07-07; source msha-controller-operator-history
- **controller_controls_mine:** Melvin  Heeman → Ober  Quarry; 2006-10-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M & M Flagstone → Ober  Quarry; 2008-07-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Melvin  Heeman → M & M Flagstone; 2008-07-08 to current/open; source msha-controller-operator-history