Paul Picha (PEE'-kuh) told The Associated Press that the trip likely won't happen until next week. If any artifacts are found, pipeline work would cease.
Picha says state officials earlier surveyed the route, but not the disputed site, which is on private land west of State Highway 1806.
Last weekend, tribal officials said crews bulldozed several sites of "significant cultural and historic value" in that area, which Texas-based pipeline company Energy Transfer Partners denies.
A federal judge allowed construction to continue there earlier this week, but is expected to rule by Friday on the tribe's lawsuit challenging federal permits.
The pipeline starts in western North Dakota and crosses through South Dakota, Iowa and Illinois.