We tested the restricted movement paradigm (RMP) for heterogeneous movement within populations using plains killifish (Fundulus zebrinus) in the Red River on the border of Texas and Oklahoma. During June–August 2020, we marked 564 plains killifish within a 5-km stream segment and recaptured 23 individuals. Recaptured individuals spent on average 17.3 days at large, moved on average 178.2 m/day, and the maximum movement observed was 935 m. Distributions of movement distances and movement rates were leptokurtic, and although distributions were skewed, there was no difference in the number of fish that moved upstream versus downstream. Our results suggest the RMP predicts broad-scale movement patterns of F. zebrinus, but fine-scale movements might be larger in magnitude compared with other Fundulus spp.