# Relationship history for MSHA mine 4503248

Current hierarchy: **Ronald G  Benson; Keith  Benson → City Transfer Inc → CTI PORTABLE**

- 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:** Keith  Benson  et al → CTI PORTABLE; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Welcome  et al → CTI PORTABLE; 1987-04-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eastside Sand & Gravel Company → CTI PORTABLE; 1991-09-01 to 1992-06-23; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Welcome  et al → Eastside Sand & Gravel Company; 1991-09-01 to 1992-06-23; source msha-controller-operator-history
- **operator_operates_mine:** Cadman (Monroe) Inc → CTI PORTABLE; 1992-06-24 to 1994-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → CTI PORTABLE; 1992-06-24 to 1994-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Cadman (Monroe) Inc; 1992-06-24 to 1994-03-31; source msha-controller-operator-history
- **operator_operates_mine:** City Transfer Inc → CTI PORTABLE; 1994-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Keith  Benson  et al → City Transfer Inc; 1994-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ronald G  Benson  et al → City Transfer Inc; 1994-04-01 to current/open; source msha-controller-operator-history