sentences:  Lake Harper was the terminal lake for the Mojave River between 40,000 and 45,000 years before present, which is also considered to be the time of highstand of the lake; the river alternatively discharged into this lake and into Lake Manix farther downstream.The timespan where the Mojave River flowed into Harper Lake began 575,000 - 475,000 years ago when the river escaped the Victorville area and entered Harper Lake until 500,000 years ago when it started alternating between Lake Manix and Lake Harper.The last time that the Mojave River reached Lake Harper was between 25,000 and 20,000 years before present, but this finding was later considered to be doubtful.