Posted by Andre Tauladan in holiday travel thanksgiving graphs on Tuesday, November 25, 2008
For those of you who already have all of your food shopping done, a menu prepared and the china and silver dusted off, we have got something just for you.
Or, for those of you who prefer to do your grocery shopping at the last minute, or maybe even just buy a pre-made meal, it will work for you too.
If you fit into either of these categories and are planning to travel for your holiday weekend be sure to check out our "best times to travel" guide for I-90 North Bend to Cle Elum, I-5 south of Olympia, and SR 16 Tacoma Narrows Bridge.
Check it out: www.wsdot.wa.gov/Congestion/ThanksgivingDay/.
Posted by Andre Tauladan on Tuesday, November 18, 2008
It may seem hard to fathom now, as we trudge through our typical cold, wet fall days, but 55 million years ago, the Pacific Northwest was a warm-weather paradise. The fossils revealed by last week’s rockslide on Chuckanut Drive (SR 11) in Bellingham are proof.
In the Eocene epoch (pronounced ee-oh-scene ee-pock), the Chuckanut Drive area looked dramatically different than the steep cliffs and rugged sandstone rock outcroppings we see today. More than 55 million years ago, the area was a lush floodplain filled with winding rivers and side channels. Large, palm-like trees, ferns and other warm-weather vegetation filled the floodplain and riverbanks.
Over time, river sediments accumulated, trapping various plant leaves and tree roots, and turned to rock. The area gradually cooled for several million years, ushering in the Pleistocene ice ages. Today, finding fossils of ferns, roots and tree leaves is a pretty common occurrence for maintenance crews cleaning up rockslides along the road.
If you’ve driven along Chuckanut Drive, you may have also noticed the various stripes and layers in the rock. Typical layers found in the Chuckanut area include sandstone, siltstone, shale, conglomerates and coal. Many of these layers are tilted and folded – an indication that the area was susceptible to tectonic activity from several faults in the area.
The makeup of the rock formations along Chuckanut Drive is also one of the main reasons we have so many rockslides during the fall and spring. Sandstone, siltstone and shale are porous, brittle rocks. Over time, when water seeps into cracks in the rock, it can dissolve and remove material holding the rock together. During the fall and spring, this is a regular occurrence along the rock outcroppings that border the highway. When enough material washes away, the rocks become unstable and can slide onto the road.
Our maintenance crews have years of experience dealing with the rocks along Chuckanut Drive. In fact, they lovingly refer to the hillside as rotten rock because of how brittle some of the rock is. You can break it apart with your fingers. As you might imagine, this presents a challenge when it comes to trying to stabilize the hillside. We’ve stabilized the slope many times during the past 20 years, and will likely continue to do so in the coming years.
The Chuckanut area is a fascinating example of the environmental forces that helped shape Puget Sound. So the next time you’re winding your way along Chuckanut Drive, try and imagine that nice, warm, tropical atmosphere from 55 million years ago.
Posted by Andre Tauladan on Friday, November 14, 2008
It’s one of the biggest rockslides to happen on Chuckanut Drive (SR 11) in the last decade. Fortunately no one was injured or hurt when several hundred yards of rock crashed onto the roadway Monday, Nov. 10. Some of the rocks were as big as small cars.
The fact that nobody was hurt had a lot to do with the decision of Area 1 maintenance supervisor Ric Willand and his team to close road and prevent drivers and crews from passing beneath the unstable hillside.
Willand was on his way to inspect an earlier slide when he found a few rocks in the road at milepost 13.3. While it’s not uncommon to find rocks all along Chuckanut Drive, it is uncommon to spot a rockslide before it happens.
While Willand was stopped at the spot, several more rocks fell onto the road. None of them were big enough to close the road. But when Willand looked more closely at the hillside, he noticed that cracks were starting to form in some of the larger rocks and that the hillside appeared to be moving.
By the next day, Willand and his team had decided to close the road. Shortly after the road was closed, guess what happened? The hillside belched and rocks spilled across the road, blocking all lanes.
As they say, hindsight is 20/20, and in this case, the decision to close the road was right on. The decision may have saved someone from serious injuries or death.
For more pictures of the slide, visit our Flickr picture account.
Read our news release for more details about the slide and how long it will take to stabilize the hillside.