# Relationship history for MSHA mine 3500515

Current hierarchy: **Wildish Land Company → Wildish Sand & Gravel Co → Wildish Sand & Gravel Co Plant #2**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Wildish Land Company → Wildish Sand & Gravel Co Plant #2; 1950-01-01 to 2008-01-10; source msha-controller-operator-history
- **controller_controls_mine:** Wildish Land Company → Wildish Sand & Gravel Co Plant #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wildish Land Company → Wildish Land Company; 1950-01-01 to 2008-01-10; source msha-controller-operator-history
- **operator_operates_mine:** Wildish Sand & Gravel Co → Wildish Sand & Gravel Co Plant #2; 2008-01-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wildish Land Company → Wildish Sand & Gravel Co; 2008-01-11 to current/open; source msha-controller-operator-history