# Relationship history for MSHA mine 3601046

Current hierarchy: **Mark  Houser; Garry W  Houser → Walter L Houser Coal Company Incorporated → Walter L Houser Strip**

- 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:** Walter L Houser Coal Company Incorporated → Walter L Houser Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Houser et al → Walter L Houser Strip; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Houser et al → Walter L Houser Coal Company Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Garry W  Houser et al → Walter L Houser Coal Company Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history