# Relationship history for MSHA mine 2901932

Current hierarchy: **Dave B  Swope → Swope Gravel → Mayhill Pit**

- 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:** Swope Gravel → Mayhill Pit; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dave B  Swope → Mayhill Pit; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dave B  Swope → Swope Gravel; 1983-08-01 to current/open; source msha-controller-operator-history