# Relationship history for MSHA mine 0405283

Current hierarchy: **Shawn T  Studebaker → Canyon Rock Co Inc → Laytonville Rock Quarry**

- 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:** Presley & Smith Gravel → Laytonville Rock Quarry; 1996-05-01 to 2003-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Ken  Smith et al → Laytonville Rock Quarry; 1996-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ken  Smith et al → Presley & Smith Gravel; 1996-05-01 to 2003-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Doug  Presley et al → Presley & Smith Gravel; 1996-05-01 to 2003-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Laytonville Rock → Laytonville Rock Quarry; 2003-07-01 to 2009-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Shawn T  Studebaker → Laytonville Rock Quarry; 2003-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn T  Studebaker → Laytonville Rock; 2003-07-01 to 2009-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Laytonville Rock → Laytonville Rock Quarry; 2009-04-07 to 2012-01-08; source msha-controller-operator-history
- **controller_controls_mine:** Taylor A.  Whitley → Laytonville Rock Quarry; 2009-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Taylor A.  Whitley → Laytonville Rock; 2009-04-07 to 2012-01-08; source msha-controller-operator-history
- **operator_operates_mine:** Laytonville Rock → Laytonville Rock Quarry; 2012-01-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn T  Studebaker → Laytonville Rock; 2012-01-09 to current/open; source msha-controller-operator-history