Sunday, October 25, 2009

Babcock Bench Hike - Frenchman Coulee to Potholes Coulee

On the east side of the Columbia River, 20 mile long Babcock Bench stretches from Trinidad to a point just north of the Interstate 90 bridge at Vantage, WA.

Ice Age floodwaters from Glacial Lake Missoula and other sources raced through the region, eroding tremendous amounts of basalt. The entablature of the Sentinel Bluffs flow was able to withstand the erosive forces of the water in this area, leaving a remarkable terrace 500 feet above the Columbia River up to one mile wide in places. Photo below provides a good look at the river and bench.

-Click any image to enlarge-

Aerial view (looking north) taken a few years ago shows mouth of Frenchman Coulee and part of the southern section of Babcock Bench. To start this October hike, I parked at the spot marked with yellow star and hiked north to Potholes Coulee. If you're considering this hike you might want to look at a shuttle so you don't need to backtrack. My hike was just over 24 miles up and back.

Babcock Bench

One of many pieces of evidence that helped unravel the Ice Age Floods Mystery.

J Harlen Bretz described Babcock Bench as " ... a very marked ledge of basalt, one mile wide in places."

The bench is for the most part, just a long flat shelf but far from featureless. Explore the river side or the wall to the east and you'll find all sorts of Columbia River Basalt formations that were shaped by the Ice Age Floods. Once columns like these were exposed by a flood, the following flood(s) would easily take apart the formation by plucking entire columns.

View from the east rim looking south over the tops of basalt columns and down Babcock Bench.

Other Ice Age Flood features found along the hike are various gravel bars, ice-rafted erratics, shallow potholes and mesas.

A few erratic boulders sit on Babcock Bench. The boulders were rafted to the area in icebergs during Ice Age Flood events. Today they look out of place in this land of dark brown basalt.

One of the nice scabland features found along the way. This mesa stands high above the Columbia River in the Sunland Estates area.

Fluted gravel bar shown is part of a much larger bar just below point where the river channel makes a slight turn to the east (see next image to view entire bar). This fluted portion of bar is just below and left of red circle #2 - next image.

1. - Sunland Estates
2. - Huge gravel bar (pictured above)
3. - Potholes Coulee

Google Maps terrain image shows hiking route between Frenchman Coulee and Potholes Coulee. I walked cross county going north and followed the old jeep road on return trip.

Several interesting cross canyons (running east to west) cut into the Bench, allow for a look at the basalt flows you've been walking on.


I guess if I'm going to stand in these for scale, I should get closer. I think this erratic must be about five feet wide. View north up bench. Great description of Babcock Bench hikes and photo of this erratic in Bruce Bjornstad's book "On the Trail of the Ice Age Floods". Notice the job the floods did scrubbing the bench. I bet this place is covered with bitterroot in the spring.

Erratic sits at N47.0883 - W120.0151

A couple small waterfalls are found between Cave B and the Columbia River. Sad face at left edge of basalt.

Quiet today as I walked by the Gorge Amphitheatre. Stroll by this place at certain times of the year and you could be listening to a rock band and 25,000 fans.

Google Earth view

1. Gorge Amphitheatre
2. Flood Bar
3. Center-Pivot Irrigation
4. Sunland Estates

Fall color in another east-west canyon cutting through bench.

1. West Bar (Giant Current Ripples)
2. Potholes Coulee

The big overhang in the south alcove of Potholes Coulee. Time for a quick lunch before heading back. If you haven't explored Potholes Coulee you're missing out ... This is one of the most amazing places (Top 5) in the entire Ice Age Floods region.

Here's a link to a paper on Potholes Coulee:
The Geomorphology of Potholes Coulee, Quincy Basin, Washington by Marc Fairbanks. A pleistocene sloth that was dug up on Babcock Bench is mentioned.

Interesting piece of basalt with plenty of gas bubbles (vesicles). Looks like it was really tumbled to have such a rounded shape.

The floods left some unfinished business here. The next flood or two shouldn't have much trouble bringing down this huge piece of entablature now that floodwaters can work all sides.

This is one cool pile of rocks. The photo doesn't do it justice ... Looks great when you can walk around and view from all angles.

This was a nice viewpoint. Easy access from another column just out of frame at right.

These hedgehog cactus are one of my favorites. Pretty healthy population of them on the other side of river. Their pink blooms in the spring are great!

Name for this island?

I followed a small stream down to the Columbia. A few salmon were swimming at the mouth of the creek. Some had expired and were scattered along the shore. Long trip from the Pacific ... I hope this was his destination.

The winery has done a nice job marking several trails below the facility.

Cave B Inn from the bench. I'm not sure if it will be there when you click on it but ... The day I posted this, the site had a great sunset photo of Babcock Bench at Cave B / Sage Cliffe.

Use your mouse to navigate around map.

WDFW driving directions to Potholes Coulee and Frenchman Coulee. Release below involves access to Potholes Coulee.

Scabland Gang Activity?
Columbia Basin Wildlife Area - Press Release
Quincy Lakes

Continuing gang-related vandalism is prompting early closure of an entrance gate to the Quincy Lakes unit of the Columbia Basin Wildlife Area in Grant County.

The Washington Department of Fish and Wildlife (WDFW) will close the unit’s south entrance gate Aug. 24. The north entrance will remain open.

The south gate closure is in response to gang-related graffiti tagging, garbage dumping and destruction of public property, including toilets, concrete walkways, parking areas and signs. Closing one entrance gate is expected to reduce unpermitted through-traffic on the north-south road through the unit. That road is traditionally closed to motor vehicles Oct. 1 through Feb. 28 during hunting season. Foot traffic is allowed year-round.

The south entrance will remain closed indefinitely. Wildlife area users are encouraged to report vandalism and any other illegal activity to local law enforcement.

For more information contact WDFW’s Northcentral Region Office in Ephrata at (509) 754-4624.


info said...

Very interesting and a nice guide Thank You.

Brad said...

Name of the island: Quilomene Island

Anonymous said...

I somehow missed this trip when you posted it. Excellent work! Nick Z.

Anonymous said...

was up there today - wish I had read this before the trip.
will take this along next time