Documentary showing an expedition through northeastern British Columbia by Mary Gibson Henry, Pennsylvania botanist and plants woman. Mrs. Henry was interested in the legendary “Tropical Valley” of northern B.C., where the warmth of hot springs supposedly fostered vegetation not otherwise found in the region. The film was shot in the summer of 1931, during the first of four such journeys she made in the period 1931-1935. Mrs. Henry was accompanied by her husband, Dr. J. Norman Henry; four of her children; topographer Knox McCusker (of the Dominion Topographical Surveys Branch); Dr. B.H. Chandler, a surgeon friend; and outfitter S. Clark, as well as various wranglers. The second and third reels of this three-reel film show the party of 16 travelling by pack-train, crossing rivers, caching food, and fishing, as well as some camp scenes. At an encampment of “Grand Lake Indians” on the Tetsa River, they engage Charlie Macdonald, the chief’s son, to guide them to Toad Hot Springs on the Toad River, but they do not proceed north to Liard Hot Springs. On the return trip south, stops include St. Paul’s Lake, Henry River, and Lake Mary and Lake Josephine [named after the Henry’s daughters]; these place names do not seem to have become official. Following the Peace River, they arrive at Hudson’s Hope (having travelled 800 miles in 79 days), and continue down river to Taylor Flats.