History of Dallas County; Visit. Recreational Areas; Trails – Land and Water; Community Services. Landfill Information; Recycling; Sheriff’s Benevolent; … Dallas County, Iowa. Attorney 515-993-5060; Assessor 515-993-5802; Auditor 515-993-6914; Board of Supervisors 515-993-5806; Clerk Of Court 515-993-5816;