461A.36  Speed limit.
  The maximum speed limit of all vehicles on state park and preserve drives, roads and highways shall be thirty-five miles per hour. All driving shall be confined to designated roadways. Whenever the commission shall determine that the speed limit hereinbefore set forth is greater than is reasonable or safe under the conditions found to exist at any place of congestion or upon any part of the park roads, drives or highways, said commission shall determine and declare a reasonable and safe speed limit thereat which shall be effective when appropriate signs giving notice thereof are erected at such places of congestion or other parts of the park roads, drives or highways.
[C39, §1828.02; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §111.36]
86 Acts, ch 1245, §1877
C93, §461A.36
For applicable scheduled fines, see §805.8A, subsections 5 and 14