US 97 - Blewett Pass Culverts Replacement

Project news

Public outreach underway to prepare travelers for a five day closure of Blewett Pass Sept. 9-14

Three culverts will be removed and replaced on US 97 near Blewett Pass in September of 2018. Two box culverts will be installed 1.5 miles north of the pass at an unnamed creek and at Five Mile Creek north of the summit.  A separate project, installs a third box culvert near the Swauk Creek campground south of the summit. The two projects will require weekday single lane closures throughout the month and one 5-day full road closure of Blewett Pass starting September 9.

  • Through September: Single-lane closures with flagger control and pilot car. Delays under 20 minutes.
  • Closure period: 9 p.m.,  Sunday, Sept. 9 to 9 a.m., Friday, Sept. 14.
    • South limit: MP 157.60, Between Mineral Springs Campground and USFS Road #9714 – Iron Creek Road, 8 miles from US 97/SR 970 intersection (“Lauderdale Junction”)
    • North limit:  MP 169, 5 miles north of Blewett Pass Summit, 16 miles from US 97/US 2 interchange (“Big Y”)
    • U.S. Forest Service roads with backside access to the work areas will be barricaded: RD 7320 (MP 159.23), RD 9711 (MP 159.27), RD 7324 (MP 163.92), RD 9716 (MP 163.89)

No specified detours - the travelers will need to determine which alternate routes work best given their starting points and destinations. US 2 over Steven’s Pass and I-90 at George (SR 281) to SR 28 through Quincy are expected to be the primary alternate routes. Expect higher traffic volumes along these routes that week.

Needs & Benefits

The current Mill culvert on Swauk Creek is a barrier to salmon and resident trout due to its size and orientation. The culverts on the north side of Blewett Pass need to be replaced because they are undersized and have a history of plugging with debris during storms, leading to washouts along the highway.


Contract #9236 for the north summit culverts was awarded to Pipkin Construction of Wenatchee April 17 for $1,088,005.00. Contract #9274 for the south summit culvert was awarded to Hurst Construction of East Wenatchee May 29 for $1,211,129.25.  Both projects will begin after Labor Day and will take 20 working days to complete (4 weeks).


Two culvert replacements are (P-3) Capital Preservation Drainage projects to increase capacity and the third is an (I-4) Capital Improvement Environmental Retrofit project to remove a fish barrier. The combined state and federal funding for the construction is $2.3 million.


Dan Lewis, Project Engineer 509-667-2880

US 97 - Blewett Pass Culverts - thumbnail map

These are the three culverts being removed and replaced that require closing the road entirely.

damage happens when the culvert can't handle the runoff

What happened when culverts failed