Mississippi Lake was created when the valley of Mississippi Creek, that runs southward through the Diablo Range, was dammed in the 20th century on the south side of
Valle Atravesado and is now a
reservoir. This reservoir was originally named
Murray Lake, named after its builder Murray Hopkins, who not only built the reservoir but the 59 miles of
County Line Road along the
divide of the Diablo Range between
San Antonio Valley and
Fifield Ranch. == Current status ==