 Six areas were studied for wild pallid sturgeon population estimates and recovery recommendations by the United States Fish and Wildlife Service (USFWS) between 1990, when the species was declared endangered, and 2006. The USFWS has referred to these six areas of wild population studies as "recovery priority management areas" (RPMAs). In the northernmost region of the study, known as RPMA 1, located between the Marias River in Montana and the western reaches of Fort Peck Reservoir, only 45 wild (nonhatchery) individuals remain. Of these, no juveniles were observed and the population was declining. In RPMA 2, located between Fort Peck Dam, the headwaters of Lake Sakakawea, and the lower Yellowstone River up to the confluence of the Tongue River, Montana, only 136 wild specimens remain. In RPMA 3, stretching from upstream of the Niobrara River to Lewis and Clark Lake along the Missouri River, no native populations were recorded. All collected specimens appeared to be hatchery-raised. However, these specimens were apparently maturing and adjusting well to this section of the river. Recovery priority management area 4 extends from Gavins Point Dam to the confluence of the Missouri and Mississippi rivers. This region also includes the Platte River. Here, at least 100 unique nonhatchery specimens were collected during the study period. Evidence also indicates some wild reproduction is going on in this region. In RPMA 5, between the confluence of the Missouri and Mississippi and the Gulf of Mexico, several hundred specimens were documented. Again, some evidence suggests natural reproduction is occurring, as demonstrated by the recovery of a few examples of immature, nonhatchery-raised individuals. The Atchafalaya River basin is designated as RPMA 6 and the findings there were similar to those in RPMAs 4 and 5, but with greater numbers of unique individuals, near 500 in total.
