Geography
Upshur County Sits on Two Major Drainage Divides
The northern part of Upshur County drains toward the Mississippi River, while the southern part drains to the Gulf of Mexico through the Sabine River system.
Upshur County straddles a continental drainage divide. Rain that falls on the northern part of the county flows eventually toward the Mississippi River basin. Rain on the southern part flows through the Sabine River system toward the Gulf of Mexico.
This geography matters for water planning, flood risk, and where lakes and creeks are located. Lake O' the Pines sits in the Big Cypress Creek watershed in the county's north. Understanding which watershed your property sits in helps when researching flood maps and water rights.
Source to confirm: Handbook of Texas — Upshur County