Minimal research has been conducted involving Salvelinus fontinalis (Brook Trout) habitat use and dispersal patterns within Adirondack Mountain headwater streams. Hence, fishery managers are left with information gaps regarding the specific habitat conditions characteristic of sustainable Brook Trout populations in Adirondack flowing waters. Through the use of single-pass electrofishing and markrecapture techniques, size-class specific microhabitat use and reach-scale movement patterns for Brook Trout were examined within two northern Adirondack streams. Water depth, water velocity, and sub strate-size use were observed to be similar among two Brook Trout size classes. Both size classes exhibited use patterns within deeper slowermoving pool habitats; however, larger Brook Trout were found to be associated with smaller-sized substrates within one of our study sites. These habitat-use patterns were also supported by comparison of stream hydrologic condition, including Froude number. Brook Trout movement patterns were found to be dependent on both size class and season. Smaller-sized trout exhibited increased movement during the spring, whereas larger trout were found to be more mobile and move more frequently during early fall. Lastly, we examined the proportion of Brook Trout moving upstream/downstream and found a greater frequency of smaller Brook Trout moving upstream during late summer.