# Relationship history for MSHA mine 3607926

Current hierarchy: **Matthew R  Mc Clain → Endless Mountain Fieldstone Supply → Quarry #1**

- 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:** Endless Mountain Fieldstone Supply → Quarry #1; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Matthew R  Mc Clain → Quarry #1; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Matthew R  Mc Clain → Endless Mountain Fieldstone Supply; 1987-09-01 to current/open; source msha-controller-operator-history