# Relationship history for MSHA mine 1202345

Current hierarchy: **Philip J  Mayer → Rock Bottom Gravel Products Inc. → Rock Bottom Inc.**

- 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:** Rock Bottom Gravel Products Inc. → Rock Bottom Inc.; 2003-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Philip J  Mayer Et Al → Rock Bottom Inc.; 2003-04-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Philip J  Mayer Et Al → Rock Bottom Gravel Products Inc.; 2003-04-07 to current/open; source msha-controller-operator-history