His North Country history, Indian Stream Republic: Settling a New England Frontier, 1785–1842, grew out of his explorations in the Pittsburg area.
Reviewing the book in the December 1997 issue of Appalachia, Gene Daniell wrote that it "gives an excellent account of the history of the Indian Stream Republic, and it also provides an evocative picture of the life of the settlements, a life hard but curiously satisfying to those who had the will and the luck to make good.
The reader will gain a great deal of insight into the lives of the people who settled the frontier regions of New England, most of whom are memorialized only by a weathered stone in a cemetery near a church or along a back road.
The family moved to Laconia, New Hampshire, where Dan worked for a manufacturing company and continued writing, hiking, and fishing.
[3] His papers are archived at Dartmouth College, and daughter Ruth has continued to compile later editions of the hiking guidebooks under the original titles.