The disclosure act stops at improved property
Idaho's Property Condition Disclosure Act, Idaho Code § 55-2501 and following, applies to residential real property, and § 55-2503 defines that as real property improved by a building or other structure with one to four dwelling units, or an individually owned unit in a structure of any size, including combined residential and commercial use. Vacant land has no building, so the act does not reach it and no statutory form is required. That does not license you to misstate what you know. It does mean the questions the form would have asked — septic feasibility, water source, flooding, boundary disputes — arrive from the buyer's side instead, usually during a due diligence period rather than up front.
Water rights are adjudicated and separately tracked
Idaho follows prior appropriation, administered by the Idaho Department of Water Resources: first in time, first in right, measured and limited by beneficial use. The Snake River Basin Adjudication ran in the District Court of the Fifth Judicial District in Twin Falls County from 1987 until the Final Unified Decree was entered on August 25, 2014, inventorying roughly 150,000 water rights across the basin. Later adjudications cover other parts of the state. The practical effect is binary: a right is either in the decree with a number, priority date, source and place of use, or it is not. Shares in a canal company or an irrigation district are a separate instrument, and they do not always travel with the deed.
There is no statewide zoning code
Idaho leaves land use to local government. The Local Land Use Planning Act, Idaho Code § 67-6501 and following, requires each city and county to adopt a comprehensive plan and zoning ordinance and authorizes subdivision ordinances, but the state does not write the substantive rules. So minimum lot size, whether a division into two parcels triggers platting, what counts as legal access, and how a private road has to be built are county questions with genuinely different answers in Kootenai, Blaine, Custer and Owyhee. Title 50, chapter 13 of the Idaho Code layers platting and vacation requirements on top. Before assuming your acreage can be split, read the ordinance for the county the land is actually in.
Access across federal land is a document
Federal agencies hold a large share of Idaho, and a route driven for years is not a right you own. A permanent road across BLM ground generally needs a right-of-way grant under Title V of the Federal Land Policy and Management Act. For private inholdings inside the National Forest System, section 1323 of the Alaska National Interest Lands Conservation Act directs the agency to provide access adequate to secure reasonable use and enjoyment, subject to its rules — a process, not a road of your choosing. Where a nineteenth century railroad grant left alternating sections in a checkerboard, parcels can meet only at a corner. Corner crossing has been litigated in the Tenth Circuit, which does not include Idaho.