TMT High Point Creek Bridge Construction
August 2015

There are a number of bridges on Tiger Mountain. In addition to short ones there are at least four bridges that are about 50 - 70 feet long. One used to be on the Tiger Mountain Trail (TMT) where it crosses High Point Creek. The floods of January 2009 caused major damage in Western Washington. King County was declared a disaster area. That opened up options for federal funding to rebuild. The folks at DNR applied for funds to rebuild the TMT bridge. The funding was approved. In 2010 they wrote an environmental assessment (EA) detailing the situation, the different options, and the environmental steps needed to replace the bridge.

The low level bridge was moved off it's concrete piers by the high water and likely big trees swept down the now huge creek. The fairly shallow but wide creek was turned into a torrent for a short time. The decision was not to rebuild in the same spot. The banks were washed out and the chances of another torrent sweeping away the bridge again were considered. The final choice was to build a 180 foot long suspension bridge. By being 110 feet longer than the previous bridge it could be set farther away from the steep banks and placed much higher above the creek. The funds were approved and the EA was approved with a finding of no significant impact (FONSI). I found the EA online in 2010 and awaited the building of the new mega bridge. The Environmental Assessment can be found here: TMT EA.

In 2011 the new bridge did not go up. I made a few detours to the bridge site and found no signs of construction. Folks were still using the trail. Some crossed on the slightly tilted bridge and scrambled up or down on the west end. Without the concrete pier it was well above the ground. Others just forded the creek as it is not deep most of the year. In 2012, 2013, and 2014 there was no action. I checked a few times and found no new information online. I had about given up on the bridge when I talked with Gary.

He was hiking on Tiger Mountain at the end of July when he did a short detour to check on the bridge site. What do you know? There were construction folks there. It was time to put up the new bridge. I hiked up to the site on Seafair Sunday arriving at 7:10 am. I expected to be alone. In fact, the construction crew was already there working. It was a mid 90s hot day and I wanted to beat the heat. The workers beat me up there. They were on a break and I asked a lot of questions and received a lot of answers. No, the suspension bridge was no longer the plan. Instead, they were building a 200' long steel bridge.  Holy cow!. That is one big bridge for a hiking trail. For a comparison, the suspension bridge over Tahoma Creek at Mt. Rainier is 200' long. Here is a link to that bridge: Tahoma Creek Bridge. That bridge is 165' above the creek. It also moves as you walk across. The TMT bridge is much lower and should be rock solid.

The contract called for the bridge to be built by August 31st. With such a short time table I decided to document the construction of the bridge. The work crew proved to be safety conscious but not averse to me standing back from the work with my camera. I got to know many of the workers over the course of nine visits. Most of August was brutally hot by Seattle standards and the last week was cool and wet as we finally had some rain.

The purpose of this feature is just to document the building of the bridge. This is likely to be the biggest hiking bridge on a hiking trail near Puget Sound. Heck, this along with Tahoma Creek might be the longest hiking bridge in the state.I can't see a flood taking this one out. The biggest danger will be falling trees. I hope it is still standing long after I'm gone. It was fun to watch the progress from holes in the ground to concrete foundation blocks to each of the 13 bridge sections going in. The construction crew are from Forks on the Olympic Peninsula. They have done logging related jobs and had no trouble moving 49,000 lbs of steel around to put the bridge together. All without a crane on site. The methods used were fascinating to me. Enough with the history lets get down to viewing the construction from start to finish.

After hearing from Gary I arrived at the work site at 7:10 am on Seafair Sunday morning. A 90+ degree day and bridge closings for the hydroplane races had me out early and back home early. I hiked up the High Point Trail to the TMT and the short distance to the creek. Much to my surprise, the construction crew beat me to the site. They had already covered the creek with logs and dug out all vegetation from the bridge span area. Holes were dug and the base frame for the coming concrete foundations were started. The guys were on a short break and I asked questions about the bridge. No to a suspension bridge. Instead it would be a steel framed bridge. Not 180' long as in the EA. It would be 200' long. I was surprised to hear that the contract called for the work to finished by 8-31-15. There was a lot to do in only a month. Especially since the site was nearly 1.5 miles from the gate where hikers park.

Eleven bridge sections had already been helicoptered in. I thought that was it. It turned out that two sections needed some modifications and were not on site until later. Those were the two sections that connect to the two vertical support beams. Without a crane I could not figure out how all those sections could be put together across a 200' space. It was clear that a crane would not be used and a helicopter would not be feasible. I had to wait a few weeks to find out just how it would be done. With much more information that I expected to garner that morning I headed home.

The Bridge Sections
Foundation Form
Bleeding Hearts
Another Look
Map Of Trail Closure
Closure Sign
--Click on thumbnails to get larger photos.--

The following Saturday I headed back to the bridge site. First I hiked up to Grand Prospect on nearby Rattlesnake Mountain. On the way home I could not resist adding another hike. Over the course of the past week the crew had nearly completed the four foundation block frames. Wooden frames filled with rebar were just about ready for concrete pouring. Unfortunately, I never saw just how the concrete was mixed and poured. Perhaps someone did photograph the job and can fill me in. Photos would be nice. It was the only major part of the job I did not see. There were no workers present so I took a good look at the bridge sections. There would be a whole lot of bolts holding the bridge together. After a thorough examination I headed back down the trail.

Back On Site
Form In Place
Lower Support Form
Closer Look
West Side Of Creek
Bridge Section Connection
Section Ends
Form Size
Bridge Span

The following weekend I scrambled up Mt. Pugh. 5300' of elevation gain was enough for me. I did not add a hike up to view the bridge. Instead, I came after work on the following Tuesday. It was still very hot but the short hike was fine. The concrete foundation blocks were done and three out of four were mostly buried. The fourth was in process as the backhoe filled in the hole. I just took a few photos and left quickly as I did not want to bother the workers. It looked like they were getting close to starting the bridge superstructure assembly. I still had no idea how they would do it.

Concrete Is Done
Lower East Block
Three Blocks
Filling In With Dirt

On Saturday I hiked back up to the site. The workers were there that morning. Not a lot had changed except for one thing. There were now three long cables going from well behind the upper east side foundation block to behind the west upper block. Clearly the cables would be used to move the eleven (actually thirteen) bridge sections into place. Another clue was the appearance of six large pulleys. They must go on the cables. This I very much wanted to see. I asked a few questions about what would come next. Assembly of the bridge was about to begin. Another short visit and I headed home.

New Items
Cables On The Ground
Cables In Trees

The next day Gary, John, and I planned a long loop hike near Mt. Rainier. The fires this summer have been the worst in state history. A few west of the Cascade Crest and a whole lot more to the east. When the wind blew to the west we were also included in the thick smoke. I had seen a lot of it on Mt. Pugh the week before. We thought going south would help to avoid much of the smoke. We were wrong. The smoke was thick at the trailhead on Highway 410. We abandoned the 15 mile hike and choked our way to Crystal Lake and back. We were done by 11:00 am. We wanted to add another hike but the smoke was everywhere. I suggested heading all the way back to the Seattle area and adding a short hike to the bridge site. It had been clear the day before. Everyone else agreed.

We did in fact miss nearly all the smoke. It seemed to be the only clear spot in the whole state. Gary had not been back since he unexpectedly ran into the crew as they were just getting started. John had not seen the site since before construction began. We do headlamp hikes on Tiger each week from fall to spring and have crossed the old broken bridge a number of times in the dark. John had crossed the creek many times on the old bridge or rock hopping. There was one major change from the day before. The three cables were now attached to trees and ran high over the site. We also took the opportunity to drop down to the creek for a better look at just how long 200' looked. It was clear that bridge assembly would be commencing very soon. I very much wanted to watch and document that part.
Cables Are Now Strung
All Six Pulleys
Relaxing On A Slab
Vertical Supports
Gary Crosses Creek
Looking East
Gary & Block
At Upper West End

On Wednesday I left work in the afternoon and headed to Tiger Mountain. I met Gary at the locked gate. Up the trail to the site we hiked and found the crew hard at work. We did not want to get booted out and were very pleased when the crew allowed us to stand, at a distance, and photograph the scene. In fact over the next week I got to know them fairly well. The first three sections had been connected on the west side. It quickly became clear how the bridge would go together. The central cable had two pulleys that held a motorized traveler, the Bridge Slinger 3. It ran along the cable from the bridge section area to where the next one would be attached. The traveler has two winches that raise and lower cables. Straps around the bridge sections were attached to the vertical cables on the traveler. That allowed each section to be lifted and dropped to the correct height.

The two outside cables had single powered pulleys with winches. They were moved to a spot on the last connected section and used to hold the bridge in place. The assembled bridge sections could be raised and lowered easily. A small generator powered the whole system. A cage/platform hung from the bridge allowed them to get underneath the bottom connections to bolt the bridge together. The real trick was getting the alignment correct for each new section. The overhead cables were where the trees were located, not necessarily exactly centered above the bridge. It turned out that the construction company is form Forks, WA and they have a good deal of logging related experience. This was a job that was well within their expertise. Gary and I watched a section moved into place and asked a lot more questions when we had a chance. After a few hours we left and headed off to hike up Tiger 1 and 2. It looked like the long hot summer was going to get some rain. Good for the fires but not for weekend hiking. We used the good weather to get in a hike.

At 7:00 pm our route brought us back to the site. The workers were all gone. We dropped down to the creek and headed over to the west side. Three sections were done. The fourth section would be over the lower west side foundation block. In fact it would be too far over to raise the 20' 11.5" vertical support beam straight up. How were then going to get it under the fourth section. Yet another mystery to me. I hoped to be back to see how. We considered walking out a short way onto the undecked superstructure but would we do something crazy like that? I'll never tell. We headed on down, just beating darkness to end an 8 mile 2800' gained hike with two bridge visits.

Construction Started
Closer Look
3 Sections In Place
Lifting Section Four
Bridge Held In Place
Non Zoomed View
Almost In Place
Working On Alignment
Attaching Section
Overhead Equipment
Back After Hike
Vertical Support Section
On West Side
4 Sections Done
60' Built
View Under Bridge
View Looking East
Heading Down

I could not help myself. The next afternoon I headed back. I was curious about the placing of the vertical support. I arrived at 2:40 pm. I was too late to see the vertical beam go up. It was now bolted to the superstructure. Section five was in place and the crew was bolting it on. After that it was time for section six. I took a number of photos and movie clips of the section moving from the area to the far east to the west side of the bridge. This was the main reason I was there. To document just how this bridge was put up far from a road and without a crane. I stayed around until the sixth section was bolted into place. For the day they added the vertical support beam, the fifth section, and also the sixth section. Six down and seven still to go. I stuck around for three hours and headed down at 5:40 pm. The drive to and from High Point on Tiger Mountain was starting to feel like a work commute. Unfortunately, I was not paid for my work. I would have one more chance to see a vertical support beam go in and I did not plan to miss it.

The crew had a very busy and successful day. Two sections added and one of the vertical support beams. They were now ready to add the center section and be more than half done with the superstructure. The center section is different than the other twelve sections. It is about 20 feet vs. 15 feet. It also marks a change in the direction of the side support pieces. One diagonal piece goes between vertical posts on each section. The angled pieces from each direction must angle up to the center vertical post. It makes it very easy to see the center of the bridge both from a distance and while crossing it.

Project Approval Form
Vertical Support Is Up
Vertical Beam Connection
Support Base
Section 5 Connection
Close Up Of Workers
Five Sections Done
Bridge Slinger 3
Next Section Hoisted
Section In Transit
Section 6 Nearly In Place
Side View
Final Adjustments
Bolting Begins
Not Quite Aligned
Overseeing The Work
Holding It Together
Finishing Section Six
6 Of 13 In Place
Tiger Mountain Trail

I actually took a day off and returned on Saturday morning. Gary met me at the gate once again. It had rained over night and more was expected this day. The workers were finishing up section nine. Section ten would be attached to the final vertical support beam. For now, the bridge had the first vertical support at about 46 feet. The other one would be 46 feet from the east end. That left 108 feet of bridge after the first support that was held up by the overhead cables. Getting the tenth section and the second vertical support would put the bridges weight back on the ground and not only on cables connected to trees. It was cold but not raining. There was a problem attaching section ten. It was not quickly solved. Gary hung around for several hours but had to leave. I was not going to miss the placement of that last vertical beam, no matter how long it took.

Just before Gary left Mike appeared. The crew greeted him by name. It looked like I was not the only bridge aficionado. Mike was on the south side and I was on the north. We were careful not to be too close to the overhead cables. We were there to document the build not to make the crew worry about our safety. After a lot of discussions and attempts section ten finally slid into place and was bolted together. Now came the vertical support.

Earlier they had lifted it from down near the creek to just east of the bridge superstructure. The traveler was moved over the beam and two straps were wrapped around it. It was raised up horizontally and moved over to the lower foundation block. What appeared to be temporary boards were set on the concrete foundation. The lower part of the beam was lowered. It was moved to where the base touched the foundation. Side support ropes were attached to keep the beam from moving laterally. The top was raised in coordination with the beam being moved west This kept tension on the beam while it remained on the foundation. Raising the last bit as it was under the end of the bridge was ingeniously done. Once in place, the bolts went on quickly. Now the bridge was 154' long and supported by the western end concrete foundation and two vertical support beams. There were just three more sections to go. Mike and I headed down together. I had not planned on a long day but the temporary problem had turned it into a 5 hour day on the site.

9 Sections In Place
Lifting Section Ten
140 Feet Of Bridge
Nearly In Place
Worker Crossing Bridge
Attaching Section Ten
Having Some Problems
It Won't Quite Fit
End View
Only 45 Feet To Go
Finally In Place!
Attaching Vertical Beam
Connected To Hoist
Moving Support Beam
Feet On Foundation
Adjusting Hoist
Beam Is Almost In Place
Support Is In Place
In Place
Time For Bolts
Misty Bridge
Working On Feet
Centering Feet
Ten Sections Done

The last day of the month fell on a Monday. It was dark and wet. I wanted to see the final superstructure and perhaps some cedar decking going into place. Groan... another drive to Tiger Mountain. I got out of town early at 1:10 pm and reached the gate by 1:40 pm. By 2:10 pm I was at the site. Sections eleven and twelve were in place. Section 13 was sitting nearby ready to go on. This was the final section. The alignment had to be perfect and the ends fastened down. There was only a little room for error. I took photos of the nearly finished superstructure. It would be some time before the final connection would be made. This day I did not feel like another wait. I still had time to get home before the usual bad afternoon traffic set in. I took it. I would be back in a few days to see the finished bridge.

Last Section
Small Gap Left
East End
One Big Bridge
East End Gap
Looking Across Bridge
New Trail Approach
Work On West End
Close Up Of Gap
New Vs. Old Level
Bridge In One Shot

Thursday before the Labor Day Weekend Gary joined me for an after work hike to the bridge site and beyond. We arrived to find that the last section was bolted on. Now all 13 sections were connected. The hand rails were more than half installed. The bridge needed to be set exactly in place so the ends could be fastened and the bottoms of the vertical supports could be grouted and bolted in place. It quickly became clear that it would take some time to finish that. Gary and I hiked up to Tiger 2. On the way down we stopped to see what was accomplished. The crew was still working at 7:00 pm. It would be dark by 8:00 pm. The key bit of information was that the decking would not be delivered until Tuesday at the earliest. No point dropping by on the holiday weekend.

We headed down the Lingering Trail at about 7:30 pm. It was almost dark when we reached the cars. It also began to rain and thunder. A near simultaneous "boom" "flash" had us leaping into our cars and taking off. The bridge was close to being done. They just needed the decking to be flown in.

Superstructure Is Done
Working On Bridge
Looking Down Bridge
Fungi Along Trail
East End Work
Support Base
Closer Look At Base
East End Connection
Jacked Up
Handrails 3/4 Done

On Tuesday Len went up to the site and posted photos. The superstructure was done. The decking had not yet been delivered. Gary was free on Thursday so I held off until then. I sure wanted to be there when it was finished. We hiked up and arrived at 3:10 pm. The superstructure was done. The vertical supports were grouted and bolted. The decking was nearly finished. They were installing boards along the bottom of the sides. Just pounding 2x4s into place. There were still some hand rails to install and part of one side of the side cables which keep things from falling over the side. Darrel thought they would be done that evening. In fact, he mentioned some of the other bridge watchers were planning a little celebration at 6:00 pm. Gary and I crossed under the bridge and headed up Tiger 2. We planned to be back by 6:00 pm.

We hiked down and arrived right about at 6:00 pm. Mike and his wife were now there. Beau, who we ran into a week earlier, was there with friends. Some of the crew's family were there. Several of the other bridge watchers brought champagne and food for the party. All that was left to do was tighten up the last couple side cable turnbuckles and cut and install a couple hand rails. At 6:25 pm the work was done. The crew posed for some photos on the bridge. We had an impromptu ribbon cutting ceremony. The bridge was done. The state still had to do their own inspection before it was officially done but as far as I was concerned it was finished. Our impromptu party lasted for an hour. We all had a good time. Plenty of good stories from the crew. They were glad to be done and soon off to the next job. They had lived at the base of the trail for much of the last five weeks. Time to head for home.

Almost Finished!
All Hands On Decking
Nailing On Molding
Old Bridge Foundation
Looking Up
Support Base
Darrel On Bridge
Looking East
West End Work
More Nailing
Heading Off To Hike
Back At 6:00 PM
Sawing Handrail
Almost Done
Last Adjustments
It's Finished!
Group Photo
Group & Family
Ribbon Cutting
Old Bridge
New Bridge

And quite a bridge it is. 200 feet 3/4 inches long. Some 38' above the creek. 49,000 lbs of steel. The one part of the job I totally missed was the concrete pour. I had no idea how they did it. I saw no equipment on site for it. I got the story at the bridge party. Cement was brought in to the end of the gated access road at the High Point exit. A helicopter picked up a bucket filled with 4000 lbs of cement. It flew up to the site and dropped the bucket attached with a 200'+ rope. The workers moved it directly over the forms where it was poured. To fill the four deep forms required 103 copter trips. That is a whole lot of work. I would have loved to have seen it.

After Gary first found out about the bridge construction on July 31st, I made 11 visits to the site over the next 5 1/2 weeks. Mostly I just stayed far out of the way and took photos and video clips. As time went by, I was able to get to know most of the crew. When they took a break, I asked questions. There were a number of times when I had no idea how they would proceed. In the case of the cement pour I had no idea even after they were done with it. Building a big bridge in the forest and away from cranes and other tools make this project so very interesting for me. Judging by the other bridge watchers I met I was not alone. Barring a big wayward tree falling, this bridge will likely far outlive me. As I cross it over the next decades I will recall all the steps required to build it. This feature will help keep it all fresh in my mind.