# Relationship history for MSHA mine 3200723

Current hierarchy: **Aaron B Potts → Bear Creek Gravel → Portable Crusher**

- 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:** Bear Creek Gravel → Portable Crusher; 1991-06-01 to 2009-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Patrick F  Anderson → Portable Crusher; 1991-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patrick F  Anderson → Bear Creek Gravel; 1991-06-01 to 2009-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Bear Creek Gravel, Inc. → Portable Crusher; 2010-01-01 to 2021-05-03; source msha-controller-operator-history
- **controller_controls_mine:** Patrick F  Anderson → Portable Crusher; 2010-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patrick F  Anderson → Bear Creek Gravel, Inc.; 2010-01-01 to 2021-05-03; source msha-controller-operator-history
- **operator_operates_mine:** Bear Creek Gravel → Portable Crusher; 2021-05-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Casey  Klein et al → Portable Crusher; 2021-05-04 to 2023-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Casey  Klein et al → Bear Creek Gravel; 2021-05-04 to 2023-06-11; source msha-controller-operator-history
- **controller_controls_operator:** Aaron B  Potts et al → Bear Creek Gravel; 2021-05-04 to 2023-06-11; source msha-controller-operator-history
- **controller_controls_mine:** Aaron B Potts → Portable Crusher; 2023-06-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Aaron B Potts → Bear Creek Gravel; 2023-06-12 to current/open; source msha-controller-operator-history