Beginning in 2007, we have inserted PIT tags into brook trout in four streams at Nash Stream State Forest in New Hampshire. We also conducted a watershed-scale study to determine the influence of barriers (culverts and waterfalls) on the genetic composition of wild brook trout in the watershed. During the study, on two of these streams, culverts that were severe barriers to upstream movement by brook trout were replaced with crossings that are not barriers to movement. On one stream, a moderate barrier was replaced, and on the fourth stream, there are no barriers to the study area. We found that the population of wild brook trout in the summer in the two streams with the most severe barriers, upon removal of the barriers, increased more so than for the other two streams. The results from the genetic work suggest that both culverts and waterfalls can be barriers, and this in turn influences the genetic composition of brook trout in the watershed. This study will continue for at least another year, at which time we will learn more about how the removal of movement barriers influences populations of wild brook trout.