# Relationship history for MSHA mine 0505157

Current hierarchy: **April J Sibson; Josh V Sibson → Sibson Gravel L.L.C. → High Country Hard Rock**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Clair  Sibson → High Country Hard Rock; 1986-08-14 to 2014-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Joshua V  Sibson → High Country Hard Rock; 2014-04-01 to 2021-04-08; source msha-controller-operator-history
- **controller_controls_mine:** April J Sibson et al → High Country Hard Rock; 2021-04-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sibson Gravel L.L.C. → High Country Hard Rock; 2022-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joshua V  Sibson → Sibson Gravel L.L.C.; 2022-10-06 to 2021-04-08; source msha-controller-operator-history
- **controller_controls_operator:** April J Sibson et al → Sibson Gravel L.L.C.; 2022-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Josh V Sibson et al → Sibson Gravel L.L.C.; 2022-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clair  Sibson → Sibson Gravel L.L.C.; 2022-10-06 to 2014-03-31; source msha-controller-operator-history