Trout Conservancy, in partnership with the Big Sky Conservation Institute, has developed an Interactive Habitat Mapper that provides a great way to determine where wild trout restoration needs in Montana are greatest based on overlapping layers of information about habitat quality. To use the Mapper, click on the layers on the right that you want, then click-and-hold to scroll out an area on the map that interests you. 303(d) refers to Montana's list of environmentally impaired waters. Also, this Mapper is still being developed, meaning that there is more information (like dewatered stream sections) yet to be included.

Link to Interactive Habitat Mapper