The request usually comes in the same week as the inspection deadline. A buyer under contract on a place off a gravel road southwest of town asks a reasonable question: can we pull the building permit file and see what was done to this house over the years?
There isn't one. Not in the way the buyer means. Custer County's own planning office answers it plainly on its website: there is currently no zoning or building code in Custer County. The county issues permits and enforces setbacks, and construction still has to meet South Dakota's rules for on-site wastewater, plumbing and electrical work. But no county inspector ever walked that house against a building code, because the county never adopted one. Which means the thing buyers assume exists as a safety net does not, and the documents that do exist are about sewage and driveways.
That sounds like a footnote. In this market it is the whole negotiation.
The septic file is the closest thing to a build record
Custer County's planning department requires a wastewater permit any time someone installs, constructs, modifies, extends, replaces or relocates a septic system, and only persons certified by the State of South Dakota are allowed to do that work. That permitting process leaves behind a real paper trail, and it is more detailed than most buyers expect:
- A perc test worksheet, performed by a certified installer.
- A site visit, where the landowner or a designee meets a Planning Department representative at the proposed location.
- An eight-foot-deep hole dug at the proposed drainfield site, which the department's representative inspects for soil depth adequate to support an absorption system.
- An inspection report that includes a sketch of the entire system, showing laterals, drainfield, seepage bed and tank, with measured distances to the house, to any on-site wells or cisterns, to rights-of-way and to roads.
Read that last item again. On a rural Custer parcel, the septic inspection sketch is often the only measured drawing anyone has ever made of where things sit on that property. It is your de facto site plan.
The setbacks it documents matter on tight Hills lots. The county's on-site wastewater requirements call for a minimum ten feet between the septic tank and the residence, twenty feet between the residence and the absorption field, and seventy-five feet between a well and the septic tank where the water surface in that well sits less than one hundred feet below the ground surface. If a home was added onto, or a well was redrilled, or a deck went out over what used to be open ground, that geometry is where a deal quietly falls apart.
There is one more line in that document worth memorizing. When an existing tank and drainfield are being reused, the property owner is required to have the tank pumped and inspected to determine its size and general condition. That is the county telling you, in writing, what a competent septic contingency looks like. Pumped and opened, not glanced at.
Then find out how you legally get to the front door
Access is the second file, and it is the one that surprises buyers coming from a city block.
Custer County requires an approach permit, approved by the County Highway Superintendent, before anyone constructs or modifies a driveway or private road access onto a public road. On acreage reached by a shared drive, that permit and the recorded plat are your access story. Ordinance #2, the county's subdivision and land use ordinance, requires that all subdivisions and roads be named, and it establishes a twenty-foot utility easement centered on interior lot lines where other suitable easements don't already exist.
None of that shows up in listing photos. All of it shows up at closing, or worse, the first winter a neighbor stops plowing.
The disclosure form is doing work it wasn't designed to do
In a county with no building code, South Dakota's seller disclosure carries more weight than it does almost anywhere else in the state. The Seller's Property Condition Disclosure Statement, codified at SDCL 43-4-44 and revised by the Department of Labor and Regulation in July 2025, asks directly about the water source, whether wastewater is handled privately, and the date the septic tank was last pumped.
The statute gives a buyer three days to terminate after personally receiving the disclosure statement or an amendment to it, and six days if it arrives by mail. Sellers who complete it truthfully are protected from liability for what they disclosed. Sellers who misrepresent or omit can be liable for actual damages and repairs, with attorney fees available to the prevailing party.
We're a real estate team and not attorneys, so treat that as the timeline that shapes your week, not as legal advice. The practical read is simple: the form is a disclosure of what the seller knows, not a warranty and not a substitute for inspection. In Custer County it is also the closest thing to an official history of the house, which is why a thin, mostly blank disclosure should slow a buyer down rather than reassure them.
Inside city limits, the file changes and so does the inspection
Cross into the City of Custer and you are buying into a system instead of a set of private improvements. City public works maintains roughly twenty-five miles of water main and twenty miles of sewer main, ten municipal wells, three iron removal plants, a booster station and five storage facilities holding about 1,230,000 gallons. The wastewater treatment plant a mile east of town was built in 1986 with a capacity of 565,000 gallons per day.
Here is the part that should change how an in-town buyer spends inspection dollars. On March 26, 2026, the state Board of Water and Natural Resources approved a $2,650,000 Clean Water State Revolving Fund loan to Custer, with $2,125,000 in principal forgiveness, to reconstruct the 5th Street sanitary sewer corridor. The stated work is replacing clay sewer mains with upsized PVC and lowering other mains, as reported when the awards were announced. The state's 2026 State Water Plan lists that project's year as 2027, and separately shows a funded Custer treatment facility upgrade and forcemain slip-lining at $18,350,100.
The city is spending that money because clay is still in the ground under older blocks. If clay mains are being replaced in the street, the private lateral running from an older house to that main is the same vintage and the same material, and nobody has ever looked inside it. A sewer scope is the cheapest inspection you can buy in Custer, and on a pre-PVC block it has the highest expected value of anything on the list.
Why all of this lands in the inspection round this year
Now the market math, because it explains why these files are worth more than a sharp opening offer.
The spring reading was slow and deep. Across the Black Hills in April 2026, the region carried 15.6 months of supply with 271 new listings entering in a single month, a median around $365,000 that was up 0.7% year over year, and a list-to-sale ratio of 98.9%. For scale, Rapid City closed 47 sales that month at a median of $354,000 in an average of 39 days.
In Custer, homes took longer. Over the three months ending May 2026, Custer's median sale price ran near $548,000 with homes averaging 77 days on market against 43 days a year earlier, while Custer County as a whole sat closer to $722,000 with about 60 days on market. A separate listing-side measure in February 2026 put Custer inventory at a median of 179 days. Those numbers don't contradict each other. Sold-side days count only the homes that found a buyer; listing-side days count everything still sitting. The gap between 77 and 179 is the market telling you how much of the standing inventory isn't moving at all.
Put the two facts together. Sellers who do sell are getting about 99 cents on the dollar of asking price, so the headline number barely bends. But homes are on the market for two to six months, and the property has no code inspection history behind it. That is a market where price is sticky and condition is negotiable, which means the money moves in the inspection and repair-credit round, over the septic, the well, the access and the sewer lateral.
For sellers, that same sentence read backward is a strategy. If the round that decides your net proceeds is the inspection round, win it before you list. Pump and inspect the tank and keep the report. Pull the wastewater permit file and the approach permit from the county. Have the plat and any easement language in a folder. If you're in town on an older block, scope the lateral yourself. A buyer who receives answers is negotiating over price. A buyer who receives silence is negotiating over risk, and risk is always priced higher than repair.
Questions we get on Custer transactions
If the county has no building code, is the house unsafe? No. It means the county did not inspect it against a code, not that anything is wrong. Work still has to meet state rules for on-site wastewater, plumbing and electrical systems. Your own inspector and the county's septic file are how you build the picture the permit history would have given you elsewhere.
Can I get the septic records before I write an offer? Start with the Custer County Planning Department at 420 Mt. Rushmore Road, which maintains the wastewater permit and inspection records along with approach permits and the permit applications index. Knowing whether a file exists at all is useful before you set your inspection period.
Does the 5th Street sewer project affect my closing timeline? Not directly. Funding was approved in March 2026 and the state plan lists the construction year as 2027. Where it matters is inspection scope, since it confirms clay mains are still in service under parts of town.
Three generations of our family have worked in this market, and the deals that go smoothly here are the ones where somebody pulled the file early. If you're weighing a Custer property or getting a Custer home ready to list, The Kahler Team will walk the parcel, the plat and the permit history with you before it becomes a deadline. We'll handle your home. Get a free home valuation to start with numbers that fit your property, not a county median.
