811 One-Call Centers and Dig Notice Requirements: WA, OR, ID, MT

Every state requires you to notify a one-call centre before excavating. The call is free, it is the law, and it only covers public utilities up to the meter. Anything private past that point stays unmarked unless you have it located separately.

Everything below is taken from the statute or rule itself, with a link to the government source. Rules change — follow the links before relying on any of it.

Washington

Dig Safe Washington / Washington 811. Call 811 or file online at digsafewashington.com.

Notice: not less than two full business days and not more than 10 full business days before the scheduled work-to-begin date, unless otherwise agreed by the excavator and facility operators in writing — RCW 19.122.030(2). Before giving that notice you must mark the boundary of the excavation area with white lining, or white pin flags where necessary. Exemptions are listed separately in RCW 19.122.031.

Positive response is now mandatory. On and after 1 January 2026, an excavator may not commence excavation until positive response has been received from every operator with facilities in the notified area — RCW 19.122.030(5). Waiting out the clock is no longer enough; you need the responses.

Marks expire after 45 calendar days from the date notice was given, and the excavator is responsible for maintaining their accuracy for the lesser of those 45 days or the duration of the excavation — RCW 19.122.030(6). Excavation after that date needs a fresh notice. Repeated re-locate requests caused by failing to maintain marks may be charged to the excavator.

Washington puts private lines on the property owner in plain terms: an end user is responsible for determining the location of a service lateral on their property and for locating the underground facilities they own. The statute also directs the one-number locator service to maintain a list of private-line locate providers who may be hired at the end user's cost — RCW 19.122.030(1)(d).

Design locating is required for any development permit within 700 feet of a transmission pipeline, and the operator has 30 days to respond — RCW 19.122.030(12).

Note for the far northeast: Pend Oreille County is served by 800-424-5555 rather than the main Washington centre.

Oregon

Oregon Utility Notification Center. Call 811 or 800-332-2344, or file online at digsafelyoregon.com.

Notice: at least two full business days, but not more than 10 full business days, before beginning excavation, under OAR 952-001-0050. Pre-marking the proposed excavation is required under OAR 952-001-0040. Both rules are in OAR Chapter 952, Division 1.

Ticket life is 30 calendar days from the date notice is given, per the definition at OAR 952-001-0010(23) as amended effective 1 January 2026. Tilling is defined as working to a depth not exceeding 18 inches, and the tolerance zone is 24 inches around the facility — OAR Chapter 952, Division 1. Older sources still quote 45 days; that figure is out of date.

Excavation excludes sidewalk, road and ditch maintenance under 12 inches deep that does not lower the original grade, and excludes agricultural tilling on private property outside a recorded right-of-way or easement.

Oregon also requires a response before you dig. An excavator may not begin excavation until a response has been received from each operator of underground facilities in the area, and may not begin more than 10 business days after giving notice, or keep excavating past ticket life, without re-notifying the Center — OAR 952-001-0090. See OAR Chapter 952, Division 1.

Operators must mark within two full business days following the day of notice, within 24 inches of the outside dimensions of the facility, and each mark must show the operator's name, initials or logo — and the width of the facility if it is greater than 2 inches — OAR 952-001-0070. If a mark carries no identifier, you do not know who to call about it. See OAR Chapter 952, Division 1.

Idaho

Three centres, and the right one depends on the county. They reorganised on 1 January 2026. Dig Safe North Idaho 811 — Bonner, Boundary, Kootenai — 811 or 800-428-4950. North Idaho 811 — Benewah and Shoshone — 866-242-5844. Digline — the other counties — 811 or 800-342-1585. Current list at the Idaho Damage Prevention Board.

Notice: not less than two business days nor more than ten business days before the scheduled date for commencement of excavation, unless otherwise agreed in writing — Idaho Code 55-2205(1). The facility owner must respond no later than two business days after receiving notice, or before the excavation time stated in the notice, at the owner's option. Excavators may not excavate until all known facilities have been marked, and once marked the excavator is responsible for maintaining the markings.

If you uncover a facility that was never located, you are entitled to standby compensation while you wait for the owner to identify it. If the owner supplies the locate information within eight hours, your compensation is capped at actual costs or $2,000, whichever is less — Idaho Code 55-2205.

Idaho has two notice exemptions, not one: excavation less than fifteen inches in vertical depth outside a recorded underground facility easement on private property, and tilling soil to a depth of less than fifteen inches for agricultural practices. Both are void if facts exist that would reasonably lead you to believe a facility is there — Idaho Code 55-2210.

Montana

Montana One Call. Call 811 or 800-424-5555, or file online at montanaonecall.com.

Montana is framed differently from the other three. The statute sets no minimum notice period for the excavator. A notification is limited to work intended to commence within 10 days and be completed within 30 days, and the facility owner must locate and mark within two business days — five business days for an engineering locate request, and as soon as practicable in an emergency — MCA 69-4-503.

If excavation has not occurred within 30 days of the marks being completed, you must request a re-mark. If that happens twice at the same site and you request a third locate, you become responsible for the cost — MCA 69-4-503(4). After a locate is complete the excavator is responsible for preserving the markings.

On private lines: a facility owner may attempt to identify a private underground facility connected to their own, but is not liable for the accuracy of that locate — MCA 69-4-503(7). If accuracy matters, have it located privately.

How long marks last, by state

There is no national figure, and the differences matter on a long project. Washington: 45 calendar days from notice, after which a fresh notice is required. Oregon: 30 calendar days ticket life. Montana: re-mark required if excavation has not occurred within 30 days of marking. In all four states the excavator is responsible for maintaining the marks once they are down.

What 811 will not mark

One-call centres notify facility operators, who mark their own lines up to the meter. They do not mark private utilities: electrical to shops, barns and outbuildings, irrigation, septic lines, private water lines, gas to a pool heater or fire pit, or anything a previous owner installed. Washington and Montana both address this in statute — Washington puts the duty on the end user, Montana removes the owner's liability for accuracy.

Advanced Underground Utility Locating Inc locates private utilities across Washington, Oregon, Idaho, Montana and northern California. Spokane and Eastern Washington: 509-710-2621. Seattle, Tacoma and Portland: 509-954-8623. Bend and Medford: 541-678-0629. Eugene and Roseburg: 541-780-4149. Coos Bay and the Oregon Coast: 541-315-6728. Emergency service is available 24 hours.

Sources

Washington: RCW Chapter 19.122 — Underground utilities (section 19.122.030 as amended by 2025 c 292).

Oregon: OAR Chapter 952, Division 1 — Oregon Utility Notification Center (definitions amended effective 1 January 2026).

Idaho: Idaho Code Title 55, Chapter 22 — Underground Facilities Damage Prevention.

Montana: MCA Title 69, Chapter 4, Part 5 — Excavations Near Underground Facilities (Montana Code Annotated 2025).

Checked against the statutory text on the state legislature and Secretary of State websites, September 2026.