# Relationship history for MSHA mine 1301907

Current hierarchy: **Travis  Stensland → Stensland Gravel Co → Washplant / Crusher**

- 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:** Chad  Van Zee → Washplant / Crusher; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rock Valley Cement Block & Tile Inc → Washplant / Crusher; 1979-01-01 to 1980-04-14; source msha-controller-operator-history
- **controller_controls_operator:** Chad  Van Zee → Rock Valley Cement Block & Tile Inc; 1979-01-01 to 1980-04-14; source msha-controller-operator-history
- **operator_operates_mine:** Stensland Gravel Co → Washplant / Crusher; 1980-04-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dennis L  Stensland et al → Washplant / Crusher; 1980-04-15 to 2021-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Dennis L  Stensland et al → Stensland Gravel Co; 1980-04-15 to 2021-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Janet K  Stensland et al → Stensland Gravel Co; 1980-04-15 to 2021-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Travis  Stensland → Washplant / Crusher; 2021-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Travis  Stensland → Stensland Gravel Co; 2021-02-01 to current/open; source msha-controller-operator-history