Where oil lands are located under the provisions of sections 21, 22 to 24, 26 to 28, 29, 30, 33 to 48, 50 to 52, 71 to 76 of this title and as placer mining claims, the annual assessment labor upon such claims may be done upon any one of a group of claims lying contiguous and owned by the same person or corporation, not exceeding five claims in all, where such labor will tend to the development or to determine the oil-bearing character of such contiguous claims.section 661 of title 43