# Relationship history for MSHA mine 4101126

Current hierarchy: **Iron Oak Energy Solutions LLC → Iron Oak Big Oak LLC → Big Oak Plant**

- 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:** Osburn Materials Inc → Big Oak Plant; 1950-01-01 to 2017-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Clay M  Tooke → Big Oak Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clay M  Tooke → Osburn Materials Inc; 1950-01-01 to 2017-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Insight Equity et al → Big Oak Plant; 2008-06-21 to 2019-12-09; source msha-controller-operator-history
- **operator_operates_mine:** Iron Oak Big Oak LLC → Big Oak Plant; 2017-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Insight Equity et al → Iron Oak Big Oak LLC; 2017-04-13 to 2019-12-09; source msha-controller-operator-history
- **controller_controls_mine:** Oak Hill Advisors et al → Big Oak Plant; 2019-12-10 to 2025-12-15; source msha-controller-operator-history
- **controller_controls_operator:** Oak Hill Advisors et al → Iron Oak Big Oak LLC; 2019-12-10 to 2025-12-15; source msha-controller-operator-history
- **controller_controls_operator:** PIMCO et al → Iron Oak Big Oak LLC; 2019-12-10 to 2025-12-15; source msha-controller-operator-history
- **controller_controls_operator:** HPS Investment Partners et al → Iron Oak Big Oak LLC; 2019-12-10 to 2025-12-15; source msha-controller-operator-history
- **controller_controls_mine:** Iron Oak Energy Solutions LLC → Big Oak Plant; 2025-12-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Iron Oak Energy Solutions LLC → Iron Oak Big Oak LLC; 2025-12-16 to current/open; source msha-controller-operator-history