# Relationship history for MSHA mine 0401949

Current hierarchy: **Tom  Cook → G3 Enterprises, Inc. → G3 Enterprises Byron 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Martin Marietta Materials Inc → G3 Enterprises Byron Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** S C R-Sibelco Nv et al → G3 Enterprises Byron Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Wedron Silica Division → G3 Enterprises Byron Plant; 1950-01-01 to 1979-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Sherman County - KS → G3 Enterprises Byron Plant; 1950-01-01 to 1979-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Sherman County - KS → Wedron Silica Division; 1950-01-01 to 1979-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Wedron Silica Company → G3 Enterprises Byron Plant; 1979-05-01 to 1979-09-11; source msha-controller-operator-history
- **controller_controls_mine:** Twentieth Century Fox → G3 Enterprises Byron Plant; 1979-05-01 to 1979-10-31; source msha-controller-operator-history
- **controller_controls_operator:** Twentieth Century Fox → Wedron Silica Company; 1979-05-01 to 1979-09-11; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → G3 Enterprises Byron Plant; 1979-09-12 to 1983-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1979-09-12 to 1983-10-13; source msha-controller-operator-history
- **operator_operates_mine:** Unimin Corporation → G3 Enterprises Byron Plant; 1983-10-14 to 2011-08-25; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Unimin Corporation; 1983-10-14 to 2011-08-25; source msha-controller-operator-history
- **operator_operates_mine:** G3 Enterprises, Inc. → G3 Enterprises Byron Plant; 2011-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tom  Cook et al → G3 Enterprises Byron Plant; 2011-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Cook et al → G3 Enterprises, Inc.; 2011-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → G3 Enterprises Byron Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Unimin Corporation; 2021-01-01 to 2011-08-25; source msha-controller-operator-history