# Relationship history for MSHA mine 4801486

Current hierarchy: **Olsen Chris R → Wyoming Asphalt Concrete & Grav Co Inc/Stc Const → LARAMIE NO 1**

- 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:** Wyoming Asphalt Concrete & Grav Co Inc/Stc Const → LARAMIE NO 1; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Olsen Chris R → LARAMIE NO 1; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Olsen Chris R → Wyoming Asphalt Concrete & Grav Co Inc/Stc Const; 1988-08-01 to current/open; source msha-controller-operator-history