# Relationship history for MSHA mine 3609793

Current hierarchy: **Maria M Morales; Bernardo  Delacruz → M&B Wallstone → M&B Wallstone**

- 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:** Demmer Flagstone Inc → M&B Wallstone; 2009-09-21 to 2020-08-19; source msha-controller-operator-history
- **controller_controls_mine:** John  Demmer III → M&B Wallstone; 2009-09-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Demmer III → Demmer Flagstone Inc; 2009-09-21 to 2020-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Shawn Colwell → M&B Wallstone; 2020-08-20 to 2024-04-21; source msha-controller-operator-history
- **controller_controls_mine:** Shawn R  Colwell → M&B Wallstone; 2020-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn R  Colwell → Shawn Colwell; 2020-08-20 to 2024-04-21; source msha-controller-operator-history
- **operator_operates_mine:** M&B Wallstone → M&B Wallstone; 2024-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Maria M Morales et al → M&B Wallstone; 2024-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Maria M Morales et al → M&B Wallstone; 2024-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bernardo  Delacruz et al → M&B Wallstone; 2024-04-22 to current/open; source msha-controller-operator-history