# Relationship history for MSHA mine 0503012

Current hierarchy: **American Electric Power Company Inc → Snowcap Coal Company, Inc. → Roadside North Portal**

- 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:** Gex Colorado Inc → Roadside North Portal; 1977-02-01 to 1981-12-30; source msha-controller-operator-history
- **controller_controls_mine:** General Exploration Company → Roadside North Portal; 1977-02-01 to 1982-03-31; source msha-controller-operator-history
- **controller_controls_operator:** General Exploration Company → Gex Colorado Inc; 1977-02-01 to 1981-12-30; source msha-controller-operator-history
- **operator_operates_mine:** Powderhorn Coal Company → Roadside North Portal; 1981-12-31 to 1987-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Canyon Coal Corp & Raven Mining Inc → Roadside North Portal; 1981-12-31 to 1987-03-30; source msha-controller-operator-history
- **controller_controls_operator:** Canyon Coal Corp & Raven Mining Inc → Powderhorn Coal Company; 1981-12-31 to 1987-03-30; source msha-controller-operator-history
- **operator_operates_mine:** Powderhorn Coal Company → Roadside North Portal; 1987-03-31 to 1997-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Roadside North Portal; 1987-03-31 to 1997-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Powderhorn Coal Company; 1987-03-31 to 1997-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Powderhorn Coal Company → Roadside North Portal; 1997-07-01 to 2001-10-29; source msha-controller-operator-history
- **controller_controls_mine:** Donn A  Chickering → Roadside North Portal; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donn A  Chickering → Powderhorn Coal Company; 1997-07-01 to 2001-10-29; source msha-controller-operator-history
- **operator_operates_mine:** Snowcap Coal Company, Inc. → Roadside North Portal; 2001-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American Electric Power Company Inc → Roadside North Portal; 2001-10-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American Electric Power Company Inc → Snowcap Coal Company, Inc.; 2001-10-30 to current/open; source msha-controller-operator-history