Methods
Field crew was based at Unalakleet and used helicopter support to visit several localities in the Nulato Hills from 9-15 July 1997 and 29 June-4 July 1998. Limited collecting was also done in the vicinity of the Unalakleet airport during both seasons. An effort was made to visit alpine areas whenever weather permitted and to revisit any areas that seemed floristicly interesting or were rich in rare taxa. In addition, several low elevation sites were visited during the 1998 survey. At each site the general vegetation was described following Viereck et al. (1992) and plant collections were taken. Each species observed was collected at least once to document its occurrence in the Nulato Hills, and further selective collecting was done at all sites to document unusual plant assemblages and the occurrence of uncommon or sensitive taxa.
Plant specimens were pressed in the field. Final identification, mounting, and data basing using 4th Dimension was undertaken at the University of Alaska Museum Herbarium, Fairbanks (ALA) where collections are now held. Duplicate 1997 collections were sent to the Vascular Plant Herbarium, Biosystematics Research Institute, Ottawa, Canada (DAO) one of the largest arctic research herbaria. In 1998, a duplicate set was sent to the Missouri Botanical Garden (MO), the home herbarium for the Flora of North America Project (FNA). A second duplicate set from both seasons were sent to the University of Alaska Anchorage Biology Department Herbarium. Nomenclature used in this report, and in the accompanying lists, is that currently used at ALA. Synonyms are included when the scientific name used at ALA differs from that used in the Flora of Alaska and neighboring territories (HultŽn 1968), the most commonly used reference for Alaska's flora.