Early Oregon Trail emigrants crossed the south flank of Flagstaff Hill and, with the Blue Mountains to the west, saw a solitary tree in the valley below. Known to French-Canadian fur trappers as l’arbre seul, this large tree, possibly a ponderosa pine or Douglas-fir, rose above the floor of Baker Valley about three miles to the northwest. For many years, perhaps centuries, it served as a landmark for Indians, trappers, missionaries, and Oregon Trail emigrants, and travelers usually stopped beside it to rest and refresh themselves. In 1843 it was cut down by an emigrant, an act John Fremont condemned as the work of “some inconsiderate emigrant axe,” and Peter Hardeman Burnett lamented as the fall of a brave old pine felled for fuel while still too green to burn.