# Relationship history for MSHA mine 0505092

Current hierarchy: **Amanda Marie  Hammerlund; Todd Edward  Hammerlund → Granby Sand and Gravel → Kattenberg**

- 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:** Granby Sand and Gravel → Kattenberg; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Todd Edward  Hammerlund et al → Kattenberg; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Todd Edward  Hammerlund et al → Granby Sand and Gravel; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amanda Marie  Hammerlund et al → Granby Sand and Gravel; 2018-04-27 to current/open; source msha-controller-operator-history