# Relationship history for MSHA mine 4104636

Current hierarchy: **Kory  Keller → Allen Keller Company → Portable Crusher #2**

- 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:** Kory  Keller et al → Portable Crusher #2; 1979-01-01 to 2016-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Allen Keller Company → Portable Crusher #2; 2006-12-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kory  Keller et al → Allen Keller Company; 2006-12-14 to 2016-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Keith  Keller et al → Allen Keller Company; 2006-12-14 to 2016-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Kory  Keller → Portable Crusher #2; 2016-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kory  Keller → Allen Keller Company; 2016-10-01 to current/open; source msha-controller-operator-history