Saturday, May 7, 2011

Minthorn Springs Wetland: Milwaukie's Best-Kept Secret

For thirteen years now, I've worked in an office located off of Highway 224, in Milwaukie.  Adjoining the office complex, there's a small wetland area called Minthorn Springs.  Looking out the office window, or as I've come and gone, I've seen lots of ducks and Canada Geese in the area, and the occasional nutria.  But in all the years I've worked there, I've never taken more than a cursory glance into the wetlands themselves.  Why is that?  I don't know.  Maybe I just don't want to hang around the office when I don't have to.

About a week ago, I finally made a special trip to go explore the wetland.  I was really surprised by the amount of habitat that's squeezed into the area's borders, and by the number of plants and animals I found. I'll take you along on my walk by posting some of the pictures I took, but first, here's a little map I made showing a good place to park, and the approximate locations and routes of the trails.  (Click the link below the map to see more details and trail descriptions.)

View Minthorn Springs Wetland in a larger map

The protected wetland area is bordered by the office complex on two sides, a railroad and residential development on one side, and by SE 37th Avenue and the Milwaukie Marketplace shopping center on the other side.  Besides the protected habitat area, there is a link to a pond at Milwaukie Marketplace, and a drainage channel along Hwy 224, which flows in to the wetlands.  After the water leaves the wetlands, it flows behind our office building and through the complex, creating more areas where the geese like to hang out.

In the maps below (created using the Oregon Explorer Advanced Mapping Tool), you can see the current wetlands in dark green.  Water from the wetlands flows SE through the industrial area to Mt. Scott Creek.  From there it turns SW, joins Kellogg Creek, then flows NW to Kellogg Lake and the Willamette River.

Map showing current wetlands and water flow (click to enlarge)

At the edge of the pond in Milwaukie Marketplace (between Sheri's and McGraths Fish House) there is a sign that says that the wetlands were once a main channel floodway for the Clackamas River, and that the area was used by Indians and pioneers.  That got me wondering about what the area looked like before parts of the wetland were filled for development.  The map below shows the current wetlands as well as historical forested and emergent wetlands.  The areas outside the historical wetlands (the light background color), are shown in the data as "prairie".

Map showing current and historical wetlands (click to enlarge)
After parking at the cul-de-sac of Minthorn Loop, I walked along the South Edge Trail (these trail names are all my invention, by the way - they're not named on any signs in the park), peeking over the chain link fence at different points as I made my way to SE 37th Ave.

Red-flowering currant (center) and Vine Maple (top left)

At the spot pictured above, where the water takes a step down as it flows toward the outlet, I saw Red-winged blackbirds in the grasses in the background, and my first Yellow-rumped Warbler (Myrtle form) was flitting around in the foreground trees.  I couldn't get a decent picture of either of them.

The story continues after the jump...

Canada Goose

Mallard pair
Canada Geese with goslings
There were lots of Canada Geese, goslings in tow, along the South Edge Trail.  The parents hissed at me as I tried to walk slowly and quietly around them.

After making it to SE 37th, I decided to go take a picture of the pond at Milwaukie Marketplace.

Minthorn Springs Pond with Hwy 224 in the background
 Then I walked up 37th to the wetlands access point, pictured below.

I entered the park and turned to the right, along the South Wetlands Trail. 

Evidence of beavers

I came upon an area covered with a plant that looked like a fern from a distance, but after taking a closer look, I don't think it is a fern.  

The leaves look similar to Pacific Bleeding Heart, but I don't think that's it either.  This plant was taller than any Bleeding Heart I've ever seen.  Anyone know what it is?  In the picture below, a Red-flowering currant tries to hold it's ground.  Update 6/6/12: I think a visitor has correctly identified this plant as Poison Hemlock (Conium maculatum).

The Canada Geese were everywhere, and they always kept a close eye on me.  I ran across a broken egg at one point.  The size made me assume it was a goose egg.  I was contemplating whether the egg had hatched, been scavenged, or otherwise broken, when I turned around and saw these...

Just lying there on the grass.  There was a pair of geese in the water nearby, but not watching me as closely as some of the geese had been.  I moved along quickly so whoever the eggs belonged to could return.
That's when I found some fresh evidence of beavers doing their thing.

Unfortunately, there are some things in the wetlands that you don't like to see...

It started to rain lightly as I was headed back to the trail head.

After making it back to the access point, I took the northern trail around the other side of the water.  The trail here was pretty muddy, with some areas that were down right swampy (as evidenced by the skunk cabbage below).

Rubus spectabilis, or Salmonberry
Bat house

Tracks in the mud

Duck house?
North of the wetlands trail head, there is a fenced off area that's undergoing restoration (Minthorn North).  You can view the area from the fence, and there are some more interpretive signs telling about the wildlife that utilizes the wetlands.

More tracks in the mud

I spent about an hour in the park, and never saw another person.  I had a great time, and I definitely won't wait another 13 years before I go back. 

It was sad to see how much trash was in the area.  The Wetlands Conservancy manages the site with the help of volunteers.  I've sent an e-mail asking about any scheduled volunteer clean-up days.  A few people with garbage bags could make a big difference here in just a couple of hours.  I'll let you know what I hear.

The South Edge Trail - wetlands on the left, mini-storage on the right

Update: February 28th, 2012 - For more recent pictures of beaver activity and a native frog at Minthorn Springs, read this post.
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