# Relationship history for MSHA mine 1514255

Current hierarchy: **Stapleton George Douglas → Stapleton Coal Company → 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

- **controller_controls_mine:** Stapleton George Douglas → No 1 Surface; 1983-06-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Stapleton Coal Company → No 1 Surface; 1983-10-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stapleton George Douglas → Stapleton Coal Company; 1983-10-05 to current/open; source msha-controller-operator-history