# Relationship history for MSHA mine 4703699

Current hierarchy: **Iron Oak Energy Solutions LLC → Iron Oak Sand LLC → Tunnel City**

- 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:** S C R-Sibelco Nv et al → Tunnel City; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Covia Holdings Corporation → Tunnel City; 2013-10-21 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Holdings Corporation; 2013-10-21 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Iron Oak Sand LLC → Tunnel City; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Tunnel City; 2021-01-01 to 2024-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Iron Oak Sand LLC; 2021-01-01 to 2024-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Tunnel City; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Holdings Corporation; 2021-01-01 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** New Covia Energy LLC → Tunnel City; 2024-07-11 to 2024-07-25; source msha-controller-operator-history
- **controller_controls_operator:** New Covia Energy LLC → Iron Oak Sand LLC; 2024-07-11 to 2024-07-25; source msha-controller-operator-history
- **controller_controls_mine:** Iron Oak Energy Solutions LLC → Tunnel City; 2024-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Iron Oak Energy Solutions LLC → Iron Oak Sand LLC; 2024-07-26 to current/open; source msha-controller-operator-history