Okla. Stat. tit. 82, § 82-603: Lands outside district, appraisement of - Bringing in

additional owners.

If the appraisers find that lands or other property not embraced

within the boundaries of the district will be necessary for or

affected by, the proposed improvement, or should be included in the

district, they shall appraise the benefits and damages to such land

and shall file notice, in the court of the appraisal which they have

made upon the lands beyond the boundaries of the district, and to

land which in their opinion should be included in the district. The

appraisers shall report to the court any lands which in their

opinion should be eliminated from the district.

Provided, that the court in determining the properties benefited

by the proposed project or projects and in assessing the benefits

derived therefrom, and in the matter of assessments for the

construction and maintenance thereof shall upon proper petition and

showing, cause to be brought in and made parties to the action all

property owners found to be benefited throughout the course of the

stream below the points of diversion of water, or to the crossing of

the state line by any such stream, whether such property be

originally included in the petition or not, such action to be taken

by the court after service of summons as required in civil actions

upon such property owners of record.