# Relationship history for MSHA mine 0700110

Current hierarchy: **Stacey R Sizemore → Porter Sand & Gravel, Inc. → Porter Sand & Gravel, 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Frank E  Porter → Porter Sand & Gravel, Inc.; 1950-01-01 to 2026-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Porter Sand & Gravel, Inc. → Porter Sand & Gravel, Inc.; 2009-10-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frank E  Porter → Porter Sand & Gravel, Inc.; 2009-10-06 to 2026-01-13; source msha-controller-operator-history
- **controller_controls_mine:** Stacey R Sizemore → Porter Sand & Gravel, Inc.; 2026-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stacey R Sizemore → Porter Sand & Gravel, Inc.; 2026-01-14 to current/open; source msha-controller-operator-history