Published
Crossing US-20 with a utility: you bore under it.
US-20 is a state highway, so the rules are the state's
US-20 runs the length of Island Park, which means a great many properties here have a state highway between them and something they need — power, water, a phone line, a service to a second parcel. The moment a utility has to cross that corridor, the authority is the Idaho Transportation Department rather than the county, and the requirement starts earlier than most people expect.
“An approved right-of-way encroachment permit will be required for all utility encroachments, including new utility installation and the relocation, maintenance, modification, or removal of existing utility facilities prior to the initiation of any work within the state highway right-of-way.”
— IDAPA 39.03.42, Highway Right-of-Way Encroachments on State Rights-of-Way, section 500.01, Approved Permit Required. Idaho Transportation Department. Rule text as amended 1 July 2024. Retrieved 1 September 2026
Read the list of what counts. It is not only new installation. Relocation, maintenance, modification and removal are all encroachments, which means digging up something that is already there is as much a permitted activity as putting something new in. Moving an existing line is not a lesser event.
You bore under the highway. You do not trench across it.
The design rule for crossings is the one that decides the cost of the job, and it sets a strong default with a narrow set of exceptions.
Conduits crossing under highways that carry utility structures — the rule names water, sewage, chemicals, electrical wire and communications cables — will be installed by jacking, driving or boring unless trenching can be justified.
Justification is not a matter of preference or convenience. The rule names what will count:
- Poor soil conditions, such as rock or boulders.
- Inadequate room for a boring pit.
- Conflicts with other utility lines which cannot be located accurately — the rule's own examples are gas lines and multiple telephone conduits.
That is a closed list of three. Cost is not on it, and neither is schedule. A contractor who would rather trench because trenching is faster has not produced a justification the rule recognises.
The three-attempt rule
The provision most worth knowing before quoting a crossing is what happens when boring is attempted and fails, which on Island Park ground is a realistic outcome.
| Situation | What the rule requires |
|---|---|
| Boring or jacking is prevented by gravel or boulders on the first attempt | At least two other documented attempts should be made at different locations before contacting the District about an alternate installation method. |
| The utility can produce documentation from a qualified agency or engineer | The rule contemplates that documentation as an alternative to repeating the attempts. |
| Any crossing at all | An approved encroachment permit before any work begins within the right-of-way. |
| Maintenance or emergency repair | Encroachment permits approved annually by the Department, with advance notice of work affecting the travelling public. |
Three attempts, at different locations, documented. On ground that is glacial and full of cobble, that is a real possibility rather than a theoretical one, and it belongs in the price before the machine arrives. The word to notice is documented — an undocumented failed attempt is not evidence of anything when the District asks.
The alternative route is worth knowing too. Documentation from a qualified agency or engineer indicating the conditions is contemplated by the rule, which means a properly evidenced geotechnical opinion may save two attempts that were going to fail anyway.
Before any of that, the practical work is establishing what you are actually crossing and what is already in there. These are the questions that decide the method and the price:
- Where does the state right-of-way boundary actually run, given it is wider than the pavement and is the line that triggers the whole rule?
- What is already in the corridor, and can each of those be located accurately rather than approximately?
- Is there room on both sides for a boring pit, and on which side would it sit?
- What is the ground made of at crossing depth, which on glacial deposits can change over a few feet?
- Is the serving utility willing to carry out the work under its own annually approved permit?
- Does the work affect the travelling public, and therefore require advance notice to the Department, which on a two-lane highway covers most of what happens in the corridor?
Maintenance is on an annual permit, not a one-off
The maintenance provision is structured differently from the installation one and is easy to miss. Right-of-way encroachment permits approved annually by the Department are required for all maintenance or emergency repairs of utility facilities, and the utility must notify the Department in advance of any work that affects the travelling public.
Two consequences follow for a landowner. The utility company serving you is likely to hold such an annual permit already, which is one reason routine work by the utility proceeds smoothly while an owner's own contractor cannot simply do the same thing. And emergency repair is inside the permit system rather than outside it — an emergency changes the urgency and the notice, not the requirement.
Where the plans end up
Final utility locations will be identified on the appropriate roadway and bridge plans. That is a short provision with a long tail: the crossing becomes part of the highway's own record, which is why the Department cares where it goes and at what depth, and why an informal crossing creates a problem that outlives the person who made it.
It is also the practical answer to a question owners often ask — whether anyone will ever know. The permitted crossing is on a plan. The unpermitted one is discovered by whoever next works in that corridor, which is exactly the situation calling 811 before digging exists to prevent from the other direction.
How to approach a crossing
- Establish whether the work is inside the state highway right-of-way at all, since the boundary is wider than the pavement and it is the boundary that triggers the rule.
- Treat relocation and removal as permit events, not just new installation. All four are named.
- Plan for boring as the method, and price it that way. Trenching is the exception and needs one of three specific justifications.
- If boring may be difficult, decide in advance whether to budget three documented attempts or to commission a qualified engineer's documentation of the conditions.
- Ask the serving utility whether the work can be done under its own annual permit, which is frequently the simplest route for anything touching its facilities.
- Give the Department advance notice of anything affecting the travelling public, which on a two-lane highway is most work.
- Keep the permit and the final location record with the property file, because the crossing will outlast the project and the next owner will need to know it is there.
The summary is short. Crossing US-20 is routine, it is permitted, and it is bored rather than dug — and the surprises are almost always in the ground rather than in the paperwork, which is the reverse of what people expect. That is worth reflecting in the estimate, alongside everything else in what excavation costs here.
Common questions
Do I need a permit to run a utility across US-20?
Yes. An approved right-of-way encroachment permit is required for all utility encroachments prior to the initiation of any work within the state highway right-of-way, and that includes new installation, relocation, maintenance, modification and removal.
Can I trench across a state highway?
Only with justification. Conduits crossing under highways will be installed by jacking, driving or boring unless trenching can be justified, and the rule names only three acceptable justifications.
What counts as justification for trenching?
Poor soil conditions such as rock or boulders, inadequate room for a boring pit, or conflicts with other utility lines that cannot be located accurately such as gas lines and multiple telephone conduits. Cost and schedule are not on the list.
What if boring fails because of boulders?
If gravel or boulders prevent boring or jacking on the first attempt, at least two other documented attempts should be made at different locations before contacting the District about an alternate installation method.
Is there a way to avoid three boring attempts?
The rule contemplates documentation from a qualified agency or engineer indicating the conditions as an alternative. A properly evidenced geotechnical opinion may take the place of attempts that were going to fail.
Does emergency repair need a permit too?
Yes. Right-of-way encroachment permits approved annually by the Department are required for all maintenance or emergency repairs of utility facilities, and the utility must notify the Department in advance of work affecting the travelling public.
Why can the utility company work when my contractor cannot?
Because maintenance and emergency repair operate under permits approved annually by the Department. A serving utility is likely to hold one already, which is often the simplest route for work touching its own facilities.
Where does the crossing get recorded?
Final utility locations will be identified on the appropriate roadway and bridge plans, so a permitted crossing becomes part of the highway's own record rather than existing only in the owner's memory.
Which authority governs — the county or the state?
For work inside the state highway right-of-way it is the Idaho Transportation Department under IDAPA 39.03.42, not Fremont County. US-20 runs the length of Island Park, so a great many crossings here fall under the state rule.