Figure 6. Map of the southern Uinkaret volcanic field showing the location of all reliable dates between 425 and 250 ka. Circa 320 ka lava Whitmore flow(s) are interpreted to have entered the canyon at river mile 187.5, where they filled paleo–Whitmore Canyon. Similar ⁴⁰Ar/³⁹Ar ages have been obtained for a small remnant at river mile 177, which probably traveled upriver based on the dip of the flow's top and the lack of upstream sources. Two ⁴⁰K/⁴⁰Ar dates on Massive Diabase remnants are included in this group, even though their correlation is questionable.