Excavation in the Methow Valley, Washington
The Methow is cobble and boulder country. Twisp, Winthrop, Carlton and Mazama all sit on it, and it is the reason a trencher is usually the wrong tool up here.
Working ground in the Methow Valley
- Valley ground here averages 35 to 70 percent rock fragments, and the river substrate runs about 72 percent cobble to boulder. That is the normal condition, not the bad day.
- Glacial fill runs about 200 feet deep around Twisp and Winthrop and up to 1,000 feet near Mazama. There is no rock floor to reach.
- Near Carlton there is dense glacial till at 26 to 40 inches, right at footing and utility depth.
- Between Early Winters Creek and Weeman Bridge the fill is so deep and coarse that surface water seasonally runs underground. Downstream, bedrock pushes it back up.
- The Carlton Complex left measured consequences here. Roughly a quarter of the burned federal ground came back strongly water repellent, and modeled erosion in a 25-year storm went from under a fifth of a ton per acre to as much as 22 tons. Undersized culverts and missing drainage dips are where it fails.
- Twisp and Winthrop each issue their own permits. Carlton and Mazama are unincorporated and fall under Okanogan County critical areas, which specifically addresses alluvial fans.
Backcountry Excavation LLC is a registered Washington contractor, licensed, bonded and insured. You can check all of it before you hire us.
Methow Valley questions
Can you trench through this ground?
Usually not with a trencher. Cobble and boulder content up here means an excavator, and that changes the time and the price. We say so up front.
Do you do post-fire drainage work?
Yes. Culvert sizing, drainage dips and protecting the toe of a fan are the three things that fail on burned ground, and all three are fixable before the next big rain.
Got a job in the Methow Valley?
Tell us where the site is and what you are trying to get done. We will let you know whether we can take it on and roughly when.