WA – Mount St Helens National Volcanic Monument, Loowit Falls

May 18, 1980 What do you remember about this event? Honestly my memory banks couldn’t recall many of the details. For those with a memory like mine, here’s a quick link from USGS, 30 Cool Facts about Mount St Helens. The Monument was established in 1982 to provide for scientific research, education and recreation. It’s another managed by the USFS.

Mount St Helens last erupted 123 years ago. It’s the most active volcano in the Cascade Range.

There are three areas to visit, westside (State Route 504), southside (Forest Road 83) and eastside (Forest Road 99). My initiation was along State Route 504 where the Johnson Ridge Observatory is located, named after a scientist who perished in the blast. I arrived on a typical drizzly Pacific Northwest Day, more common in June than in mid July.

The mountain said, nope not today. Factoid: “Within 3 minutes, the lateral blast, traveling at more than 300 miles per hour, blew down and scorched 230 square miles of forest.” Source: USGS 

Okay maybe a peek at my peak. Factoid: “The largest terrestrial landslide in recorded history reduced the summit by 1,300 feet and triggered a lateral blast.”  Source: USGS 

I took a short hike on the Boundary trail focusing on the flowers.

Loowit Falls

The next day with much improved weather, I was off to find Loowit Falls.

Dropping down from the ridge into the blast zone reminded me of my Grand Canyon experiences. You have to drop into the belly to experience the hidden gems. It’s hard to imagine this area now known as Pumice Plain once a thick forest.

Loowit Falls are ON the mountain so I’d be crossing the Pumice Plain.

What looks like dried grass is actually a mossy wildflower carpet.


Just think, it took nearly 40 years to achieve this much growth. Reminds me of how slowly forests regenerate after extremely hot forest fires. Factoid: “Small plants and trees beneath winter snow, and roots protected by soil, survived the May 18, 1980 eruption and now thrive. Thousands of birds, mammals, reptiles, amphibians, and millions of hatchery fingerlings perished in the eruption. Late May 1980—Wind-dispersed spiders and scavenging beetles were among the first animals to return to the Mount St. Helens area. The landscape devastated by the eruption has evolved into a rich and diverse habitat for plants and animals.”

In fact some areas included thick bushes, predominantly Sitka Alder, streams, trees and more water loving flowers.

There were large tent caterpillar nests, in fact the largest I’ve ever seen.

Who was Harry Truman? I was hiking toward Harry’s Ridge and descending in the canyon on the Truman trail.

I assumed there must have been a President Harry Truman connection, but no, this was a very different Harry Truman.

This is Harry’s Ridge, which is said to offer the best views of Spirit Lake. I didn’t hike the ridge during this trip.

It was interesting to see newly formed ponds and water channel changes. The mounds are known as hummocks, created by earth blasted from the mountain. 

Geology was everywhere. I’m guessing this is a lava bomb.

You’ll find Loowit Falls in the middle of this photo. Factoid: “March 20, 1980—A magnitude 4.2 earthquake signaled the reawakening of the volcano after 123 years.”




When I started seeing white fur, my mind went to mountain goats. I couldn’t help but wonder.

As I neared the falls, why yes, I spied a goat.

Soon enough I found the herd.

Spirit Lake

When I saw the white on the lake, my first thought was ice. Given temperatures and snow levels, I was confused. Well sure enough it was floating logs, a so called log mat covering 40% of the surface with about 350,000 acre-feet of pyrolized trees. There is now 200 feet of sediment in the lake increasing the diameter nearly three fold. Harry Truman and his lodge are buried beneath that sediment. Factoid: “Prior to 1980, there were six camps on the shore of Spirit Lake: a Boy Scout camp (Columbia Pacific Council), a Girl Scout camp, two YMCA camps (Longview YMCA camp Loowit, and Portland YMCA camp), Harmony Fall Lodge, and another for the general public. There were also a number of lodges catering to visitors, including Spirit Lake Lodge and Mt. St. Helens Lodge; the latter was inhabited by Harry R. Truman, who became one of the volcano’s victims.”

I was curious about the source of the lake and found this from USGS,

Research suggests that Spirit Lake is an intermittent lake: it has been repeatedly dammed by volcanic material, filled to capacity with water, and at least partially drained due to dam failures causing several major floods and lahars down the North Fork Toutle River. It is believed that pyroclastic flows around 3,350 years ago first dammed the river to form the lake, and then it overflowed and was likely dammed again by debris avalanches prior to the May 18, 1980 eruption.

In early 1980, Spirit Lake was the source of the North Fork Toutle River. However, this changed when the 18 May debris avalanche deposit blocked the outlet of Spirit Lake, and caused the volcano’s newly formed crater to become the source of the river. The debris avalanche raised the surface elevation of Spirit Lake 64 m (210 ft) and filled its natural outlet to a depth of 84 m (276 ft). Without an outlet, runoff from rain and snow caused the lake level to continue to rise, which threatened to breach the unstable blockage.

In November 1982 a pumping station and pipeline were installed to regulate the rising level of Spirit Lake, while a tunnel was bored through bedrock to provide a permanent, stable outlet. Water released from the pump outlet fed into the North Fork of the Toutle River. In May 1985, the tunnel connecting Spirit Lake and South Coldwater Creek was opened.

This photo I took from a hike up Mount Margaret does a better job showing the log mat. It’s hard to imagine the blast caused an 800 foot wave that pushed water and debris over Johnson Ridge. So many questions, did Johnson Ridge exist before the blast? Did the height change?

You can zoom this photo to see the location of Harry’s Lodge.

There were plenty of reminders that this is an active study area.

Adventure Date(s):

  • July 17-18, 2019

Hike Details: Tips:

  • This was one of those places where there aren’t public lands near the trailheads on the Johnson Ridge side. It makes for nearly impossible dispersed camping. Backcountry camping permits are tough to obtain. I stayed at Seaquest Campground. While spendy for my budget, at least they have forested semi-private campsites. The biggest issue is that you cannot get a walk-up permit until after 2:30pm. Sites are priced based on popularity. It’s a 50-mile drive from the campground to Johnson Ridge so not something I wanted to do daily. One b..onus however is that they do have showers.
  • I stopped at the Visitor Center in Castle Rock. The rangers were knowledgeable and helpful with getting basic maps and hiking trail info. The interpretative displays require a fee separate from your Park Pass. Save your money and time for Johnson Ridge.
  • It’s worthwhile spending time at the Johnson Ridge Observatory. I found the film very informative.
  • Loved their cartoon reminders.