# Relationship history for MSHA mine 1401795

Current hierarchy: **Clark County-Ks → Clark County Road and Bridge → Portable #1 (Sandplant)**

- 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:** Clark County-Ks → Portable #1 (Sandplant); 1981-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Clark County Road and Bridge → Portable #1 (Sandplant); 2018-02-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clark County-Ks → Clark County Road and Bridge; 2018-02-21 to current/open; source msha-controller-operator-history