From the south end of the Windy Ridge parking lot there is a
dirt service road. From there you may ride a bike to the end. There
you must leave your bike and begin your hike on the Windy Trail
(216E). Then right on Loowit Trial (216) and left on Loowit Falls
trail (216F). No dogs. Parking permit required at Windy Ridge. Must
stay on trail and leave all natural features as is! Conditions can
be variable. Blowing ash, wind, and rain are common. Round trip is
about 8.7 miles (about 4.7 biking/ 4 hiking)
As to the uniqueness of this Earthcache; This
is the focal point of where the eruption occurred. Here is where
the initiating landslide and much of the mountain slid away, and
where just overhead the released pressures of the lateral blast
took place.
Ten years before the eruption of Mt Saint Helens I climbed to
its summit. Every part of the mountain that I touched that day is
gone. 1314' of its 9677' summit is now gone, 0.67 cubic miles of
its volume removed. The Mount Fuji of the northwest became a bleak
gray shell of its former self. That day we climbed to the right of
Dog's Head up the Lizards. Remnants of Dog's Head still remain as
the Northeastern edge of the crater rim. These coordinates are
close to where we began our climb that day. How things have
changed. Let me begin with some stark facts, and then I will
provide 6 questions, 3 of which you must answer to claim this find,
and of course everyone would love to see your photos as well.
May 18, 1980, at 8:32 in the morning, exactly 12 days before my
wedding, St Helens had a 5.1 magnitude earthquake that triggered
the largest landslide in recorded history removing much of the top
and north side of the mountain, that slid down into Spirit Lake
displacing all of its water in a 200' wave, sending it into and up
the surrounding mountain walls, and heating it to body temperature.
Overtaking this slide was a blast of hot gases traveling at at
least 300 mph (tree evidence suggests 670mph) and a temperature of
660 degrees at the dead tree zone, and having a force of 24
megatons of thermal energy. As the blast lost energy and slowed it
lost its carrying capacity, dropping its load of pumice, rock and
ash. Once this occurred the hot gasses were released upward thus
leaving clear boundaries of destroyed forest and standing trees. At
the mountain, a vertical eruption column sent ash and gases 80,000'
feet up.
Later, near noon, a second eruption occurred causing pyroclastic
flows (ash, pumice, and gas) at up to 80mph and at up to 1500
degrees, to 5 miles from the mountain cooking all in its path.
Lahars (mudflows) as well were occurring during this whole process.
Heated water, ash, and pumice traveled down both sides of the
mountain at 25 mph ripping out trees and bridges covering
everything in a cement type mixture.
Where you are standing now, things would not have been good. You
probably would be spread out between the north end of Spirit Lake
and Kansas.
Today where you are standing, if you hear a roar or rumble run
uphill. Maybe it will help. Look around you. There is a reason why
things look a bit scoured. Consider also that you are somewhere
below a gathering lump of hot pastie rock called the lava dome, and
surrounded by hills and walls of loosely placed rock. Your
elevation here is 4560'. The new summit rim is 8363', and the
crater is 2084' deep, with its floor at 6279'.
To log this cache answer any 3 of the 6 questions in an email to
me. Remember, we all love photos.
1. Directly across the across the blast zone from you, you will see
three hooked peaks. The one in the middle is Coldwater Peak. Below
that you see two ridges causing a wedge above the blast flats. What
geological structures lays in the base of this wedge?
2. How do you think it was formed?
3. In the distance you will see Johnston Ridge Observatory. What is
the magnetic compass bearing from you?
4. What vivid feature do you see in the hill directly above the
falls?
5. It has been thirty years since the eruption, yet plant growth
along the way is stark, and limited to mostly grass and flowers.
Give two reasons why?
6. One stream bed along the way is vastly different from all the
other stream beds. How so?