# Relationship history for MSHA mine 1515190

Current hierarchy: **Holbrook Martin--Eddie Wampler → Oliver Bolling Jr Construction → No 1 Surface**

- 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:** Oliver Bolling Jr Construction → No 1 Surface; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holbrook Martin--Eddie Wampler Et Al → No 1 Surface; 1985-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holbrook Martin--Eddie Wampler Et Al → Oliver Bolling Jr Construction; 1985-04-01 to current/open; source msha-controller-operator-history