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Northwest Road Conditions and Chain Laws for Truckers

Chain rules last checked against official sources on October 31, 2026.

This page covers road conditions and chain rules for truckers and other truck drivers in Washington, Oregon, Idaho and Montana. The chain rules below are checked against official state sources and linked to them.

The map shows mountain passes, National Weather Service forecasts and alerts, NOAA radar and work zone data from Washington and Idaho. Each reading shows the agency that published it and a "current as of" time. Road and chain reports for Oregon and Montana, and chain status everywhere, are on the state sites linked below.

Not an official road report. Check posted signs and the state DOT before you drive. Do not use this page while driving: pull over where it is safe, or ask a passenger to look.

Road map for truckers in Washington, Oregon, Idaho and Montana

Official reports (these work without the map):

The map loads as it comes into view. It shows mountain passes, National Weather Service forecasts and alerts, NOAA radar and work zones.

Road closures and conditions

The map's work zone layer shows construction and work zones from the Washington State DOT and Idaho Transportation Department feeds, including the ones that close all lanes. It does not show weather closures or chain requirements.

Weather closures and chain requirements, such as those on I-84 at Cabbage Hill near Pendleton, are posted by each state. Check TripCheck for Oregon, WSDOT for Washington, Idaho 511 for Idaho and 511mt.net for Montana. Montana is a link-out only for now.

Chain rules for truckers by state

Chain rules for commercial trucks in Washington, Oregon, Idaho and Montana, each checked against the state's official source. Posted signs and the DOT in charge decide what applies on the day. This is general information, not legal advice. The sources do not describe drag chains or other traction devices beyond what is written here, so ask the state before you rely on one.

Washington chain law for trucks

Vehicles over 10,000 pounds gross vehicle weight rating (GVWR) must carry sufficient tire chains from November 1 to April 1 on designated mountain routes, and at other times when chains are required. The listed routes include I-90 from North Bend to Ellensburg (Snoqualmie Pass), I-82 from Ellensburg to Selah, US 2 from Dryden to Index (Stevens Pass), US 12 from Packwood to Naches (White Pass) and parts of US 97, SR 14, SR 20, SR 155, SR 410, SR 542 and SR 970. Vehicles making local deliveries shown on the bill of lading that do not cross a mountain pass are exempt if they operate outside a chain required area.

When "chains required" signs are posted, a 5-axle tractor with dual drive axles and a tandem-axle semi-trailer must chain at least four tires on the drive axles (all tires on one drive axle, or one tire on each side of each drive axle) and one tire on either of the trailer's last two axles. Every vehicle over 10,000 pounds GVWR must carry at least two extra chains. Chains need two side chains with hardened metal cross chains, and plastic chains are not allowed. If automatic chains are used, regular chains must be carried for the outside drive tires. WSDOT or the Washington State Patrol may stop a vehicle from entering a chain control area if it would struggle to travel safely.

Fine: this page states none, because WAC 204-24-050 does not give one.

Official sources:

Oregon chain law for trucks

Oregon's chain law applies to all highways in the state. ODOT says all commercial vehicles over 10,000 pounds GVW must carry chains whenever road conditions might require them or Snow Zone signs are posted. When signs say chains are required, a vehicle that is towing or is rated over 10,000 pounds GVW must use chains, and traction tires do not replace them. Chain placement depends on drive axles and trailers. For example, a tandem-drive truck-tractor towing a semitrailer needs chains on two tires on each side of the primary drive axle (or one tire on each side of each drive axle if both axles are powered) and on two tires, one on each side, of any semitrailer axle (OAR 734-017-0010).

In very bad conditions ODOT can order a conditional road closure that requires chains on all vehicles. ODOT says these are frequent in winter on I-5 through the Siskiyou Pass south of Ashland.

Fine: failing to use chains where posted is a Class C traffic violation. For vehicles registered under ORS chapter 826 (commercial and prorated vehicles) the presumptive fine is $880 (ORS 815.140).

ODOT ties the carry rule to road conditions and posted Snow Zone signs, and none of the pages checked gives a calendar carry season. Check TripCheck for Snow Zone and chain notices before every trip. By phone, call 511 inside Oregon or 1-800-977-ODOT (6368), or 503-588-2941 from outside Oregon (ODOT page).

Official sources:

Idaho chain law for trucks

Idaho Code 49-948 covers Lookout Pass and Fourth of July Pass on I-90 and Lolo Pass on US 12. If the Idaho Transportation Department (ITD) decides conditions there are unsafe, it may require chains on commercial vehicles. When it does, ITD must give multiple advance notices, provide pull-outs, warn at a point where trucks can safely leave traffic before chains are required, and never post a chain requirement on bare pavement.

The requirement is met by chaining at least one tire on each side of one drive axle (regardless of how many drive axles) and one tire on each side of one axle at or near the rear of each towed vehicle. Variable load suspension axles and converter dollies do not count. Another traction device that provides traction equal to or better than chains may be used. Exemptions include trucks hauling agricultural products at any time of year, forest products (including chip trucks), mine products such as sand, gravel and aggregates (but not petroleum products) and tow trucks.

The statute sets no carry season, and this page states no fine for Idaho.

Official sources:

Montana chain law for trucks

From October 1 through April 30, a motor truck of 26,001 pounds GVW or more that is towing a trailer must carry approved traction control devices on a mountain pass or on any stretch of highway the Montana Department of Transportation (MDT) designates as a place where traction devices may be needed. Four-wheel-drive vehicles are exempt. The fine is $225 for a first offense and $225 to $500 for later offenses (MCA 61-9-436).

When MDT decides chains are required, every vehicle towing a trailer must chain the drive wheels of one axle. AutoSocks are an approved alternative. MDT posts chain-up and chain-removal areas. MDT's list of places where chains may be required includes Lookout Pass (I-90, west end at the Idaho line, westbound), Homestake Pass (I-90 mile markers 228 to 241), Bozeman Hill or Bozeman Pass (I-90 mile markers 319 to 323), Lolo Pass (US 12 at the Idaho line, westbound) and MacDonald Pass (US 12 mile markers 23 to 35). Studded tires are allowed from October 1 to May 31.

Check the posted signs and 511mt.net. Monida Pass (I-15) is not on MDT's chain list, so this page makes no Montana chain claim for it.

Official sources:

Mountain passes on this map

Marker positions are approximate. Elevations are shown only where an agency source states them. Pass names and routes follow the agency pages linked in each row.

Washington passes

PassRouteElevationOfficial report
Snoqualmie PassI-903,022 ftWSDOT report and cameras
Stevens PassUS 24,061 ftWSDOT report and cameras
White PassUS 124,500 ftWSDOT report and cameras
Blewett PassUS 974,102 ftWSDOT report and cameras

Oregon passes

PassRouteElevationOfficial report
Cabbage Hill / Deadman Pass (Blue Mountains)I-84, MP 216 to 2334,193 ftTripCheck report and cameras
Santiam PassUS 20, MP 71.59 to 884,817 ftTripCheck report and cameras
Siskiyou PassI-5 south of AshlandNot listedTripCheck report and cameras

Idaho passes

PassRouteOfficial report
Lookout PassI-90, Idaho and Montana lineIdaho 511 report and cameras
Fourth of July Pass (4th of July Pass)I-90Idaho 511 report and cameras
Lolo Pass (US 12, Idaho and Montana)US 12, Idaho and Montana lineIdaho 511 report and cameras
Monida PassI-15, Idaho and Montana lineIdaho 511 report and cameras

Montana passes

PassRouteOfficial report
Homestake PassI-90, MM 228 to 241511mt.net report and cameras
Bozeman PassI-90, MM 319 to 323 (MDT: Bozeman Hill)511mt.net report and cameras
MacDonald PassUS 12, MM 23 to 35511mt.net report and cameras

High wind on the Columbia River Gorge and I-90 near Livingston

Strong crosswinds can push high-profile trucks, such as empty trailers, off line. This page shows National Weather Service wind forecasts and alerts such as High Wind Warning and Wind Advisory for points along I-84 in the Columbia River Gorge (Hood River, The Dalles and Arlington) and I-90 at Livingston, Montana.

This page states no wind restriction for either road. Wind rules and closures for high-profile vehicles come from the state DOT, so check TripCheck and 511mt.net and the posted signs.

Weather radar and NWS alerts

The radar layer is NOAA national radar reflectivity (the strength of returns), updated about every five minutes while it is switched on. It does not separate snow, rain and mix, so use the National Weather Service forecast and alerts for the precipitation type.

The alerts layer draws National Weather Service watches, warnings and advisories on the map. The list under the map names the ones for Washington, Oregon, Idaho and Montana. Weather data is from NOAA and the National Weather Service. Their use here does not mean they endorse Big Rig Daily.

Your location stays on your device

The "Use my location" button runs only after you tap it. Your position is used in your browser to center the map and to ask the National Weather Service for a forecast and alerts at that spot. It is not sent to Big Rig Daily servers or analytics, and the page does not store it. The National Weather Service and the map tile providers see the request, as they would for any map or forecast.

If you refuse the permission prompt, or you are outside Washington, Oregon, Idaho and Montana, the page tells you and nothing else happens.

Where the data comes from

Construction and restriction details beyond the work zone layer, truck parking and rest areas, ports of entry and scales, and a route view for I-84, I-90, I-15, I-5 and I-82 are not on this page yet, and camera images are not shown until each agency's terms are reviewed.

Frequently asked questions

Do truckers need chains in Washington?

Vehicles over 10,000 pounds GVWR must carry chains from Nov 1 to Apr 1 on listed mountain routes, including I-90 over Snoqualmie Pass, US 2 over Stevens Pass and US 12 over White Pass. When "chains required" signs are posted, a 5-axle tractor with a tandem semi-trailer must chain at least four drive tires and one trailer tire, and carry two extra chains (WAC 204-24-050).

Is Cabbage Hill on I-84 closed right now?

This page cannot tell you, because weather closures are posted by ODOT. Check TripCheck.com for the current status. ODOT describes Cabbage Hill (Emigrant Hill) as a seven-mile downgrade, 35 miles west of La Grande, with "some of the most changeable and severe weather conditions in the Northwest."

What are Oregon's chain rules for semis?

Oregon's chain law applies on every state highway. Commercial vehicles over 10,000 pounds GVW must carry chains when conditions might require them, and must use them when chains-required signs are posted. Traction tires do not replace chains for these trucks. The presumptive fine for registered commercial vehicles is $880 (ORS 815.140).

Does Montana require trucks to carry chains?

From Oct 1 to Apr 30, a motor truck of 26,001 pounds GVW or more towing a trailer must carry approved traction devices on mountain passes and MDT-designated stretches of highway. Four-wheel-drive vehicles are exempt. The fine is $225 for a first offense (MCA 61-9-436).

Does Idaho require chains on Lookout Pass?

Only when ITD declares unsafe conditions and posts a requirement. Idaho Code 49-948 covers Lookout Pass and Fourth of July Pass on I-90 and Lolo Pass on US 12. ITD may not post a chain requirement on bare pavement.

Where do the reports on this map come from?

Weather alerts, forecasts and radar come from the National Weather Service and NOAA. Work zones come from the Washington and Idaho DOT feeds. Closures, chain status and cameras for all four states are on the DOT sites linked on this page (WSDOT, ODOT TripCheck, Idaho 511 and Montana 511), which this page does not copy yet. Each reading shows a "current as of" time.

Does Big Rig Daily save my location?

No. The "use my location" button only runs after you tap it. Your position is used in your browser to center the map and ask the National Weather Service for a forecast. It is not sent to our servers or analytics.

Is this page an official road report?

No. Big Rig Daily is not a government agency. NOAA and NWS data appears on this page without implying endorsement. Always check the posted signs and the state DOT before you drive.

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