Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska

Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska, Geophysical Report 2025-2, covers parts of the Nulato and Ophir quadrangles south of Galena, Alaska. Time-domain electromagnetic data were collected with the helicopter-mounted SkyTEM 306HP system from July 22 to August 19, 2024, by SkyTEM Canada Incorporated. A total of 5,823.4 line kilometers were collected over a single survey block covering 2,037 square kilometers. Two special sub-survey blocks were defined to increase data coverage of specific holdings: the North Block--funded in collaboration with Doyon, Limited--and the South Block--funded in collaboration with Western Alaska Copper & Gold. The main survey block was flown with east-west line orientation and a nominal line spacing of 400 meters. The North Block was flown with an infilled effective line spacing of 200 meters, and the South Block was flown with an infilled effective line spacing of 200 meters, including north-south oriented lines in addition to east-west oriented lines The mean ground clearance was 45.8 +/- 10.2 meters with a nominal survey speed of 89.6 +/- 14.7 km/hr. The data were inverted to create two subsurface resistivity models, agf_sci and skytem_lci, presented herein. The data, as well as additional metadata, are available from the DGGS website: http://doi.org/10.14509/31304.