The four Benham Caches (Fort Benham, Benham View, Benham Falls, and Benham
Bonus) are located on the Benham Buttes which are a group of 1.8 million year
old rhyodacite domes. Access to the area is from the road to West Benham Falls
trailhead. There are some roads into the area but the area is posted as no motorized
vehicles so please respect the closure. Many of the roads overgrown but still
make great hiking or biking trails. The first three caches can be done individually
or all at the same time as part of a 5 mile loop. To do the Benham Bonus cache
you must do the other three first.
Cache is an ammo can.
Waypoint 1.
N 43° 56.040'
W 121° 25.343'
Small metal tag.
X = Tag Number
AAA = X + 129
BBB = X - 55
Waypoint 2.
N 43° 55.AAA'
W 121° 24.BBB'
To the southeast is Newberry Volcano, which is a massive shield volcano covering
some 500 square miles (an oval shaped area about 30 miles north-south and 20
miles east-west).
The area to the south and southwest is underlain by the Bend basalt. About
80,000 years ago this flow from Newberry pushed the Deschutes River westward
against Benham Buttes. Much of the flow pasted through Lava River Cave and another
branch went north to underlie Bend and extend almost to Redmond. Over the next
70,000 years the river cut a new channel along the margin of the flow. Near
this point there was a canyon which was about a 100 feet deeper than today’s
channel.
To the east is Lava Butte and its lava flow. The eruption occurred 7000 years
ago and again blocked the Deschutes River. The flow filled the deep canyon of
the Deschutes and formed a lake which extended up river beyond the Sunriver
area. As the lake rose, the lowest point was a low saddle on Benham Buttes.
As the lake overflowed it cut the channel that is now Benham Falls. For
more details on the geology check here.
Small metal tag.
Z = Tag Number
C = Z - 782
DDD = Z - 5
Cache
N 43° 56.00C'
W 121° 24.DDD'
Be sure to record the Benham Bonus Number from log book or container lid. 7/3/05-Note the number on the container is wrong, it needs to be increased by 4.