During the drought (1952-1956) the mainstream with its turbid water and mud bottom could hardly have served as a refugium for species requiring the clear water and gravel bottom of upland tributaries. Probably the main refugia for these species [group (3)] were in the upper portions of Rock Creek, Washington Creek and possibly Deer Creek. While collecting we observed that these creeks had larger proportions of gravel-rubble bottom, clearer water, deeper pools, and appeared to be more stable than other creeks in the drainage. In Washington Creek, Lone Star Lake enhanced stability of flow. At the end of the drought, fishes in group (3) probably were extirpated or decimated in other tributaries of the Wakarusa. After normal flow recommenced in 1956, fishes re-entered the previously uninhabitable streams or stream-segments. The rate of redispersal by various species probably depended upon their innate mobility, and upon their tolerance of the muddy mainstream of the Wakarusa. Our observations suggest that certain species in group (3) dispersed rapidly from refugia in Rock Creek, Washington Creek, and possibly Deer Creek. These species may, of course, have survived in a few remaining pools in tributaries throughout the basin, thereby necessitating only minor redispersal within these tributaries following drought. Species of group (3) that were most tolerant of drought or that dispersed most rapidly are _Catostomus commersonnii_, _Notropis umbratilis_, _Pimephales notatus_, and _Percina caprodes_; these were present in the uppermost portions of the basin in 1959. Fishes having lesser capacity for survival or dispersal are _Semotilus atromaculatus_, _Notropis topeka_, _Phenacobius mirabilis_ and _Campostoma anomalum_; in 1959, they were not found farther upstream than Burys Creek. _Etheostoma spectabile_, the orangethroat darter, was taken in Rock Creek, Washington Creek, Deer Creek, Strowbridge Creek, Elk Creek, and at station 24 on the Wakarusa. This is a riffle-dwelling, comparatively sedentary fish, not a strong swimmer. These traits, coupled with the long, muddy pools and infrequent riffles of the Wakarusa mainstream, provide a reasonable explanation of the comparatively slow rate of dispersal by the orangethroat darter.