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North & South Maybe Mines

North Maybe Mine
North Maybe Mine


The Maybe Canyon Mines (North and South) are located on the east side of Dry Valley, about 17 miles northeast of Soda Springs, in Caribou County, Idaho. The mines together are over 3½ miles long and are located on federal Lease I-04.

Although phosphate ore has been known in this area since the latter part of the nineteenth century, it wasn’t until 1910 that the ore deposits were investigated in any detail. In that year, the US Geological Survey (USGS) conducted field investigations of the phosphate. The USGS also investigated in the vicinity of Maybe Canyon in August and September 1948.

The trenching activities of the USGS during 1948 apparently attracted commercial interest. On September 7, 1948, the J.R. Simplot Company applied to the federal government for a lease of the phosphate ore in the Maybe Canyon area. On March 14, 1949, the company withdrew its application from consideration. The Bureau of Land Management (BLM) continued to look at this area for leasing, and on May 25, 1949, the BLM held a competitive lease sale for the phosphate resources of the Maybe Canyon area. Of three bidders at the sale, the Western Fertilizer Association (WFA) of Salt Lake City, Utah, was the the successful high bidder for federal lease, I-04. The two other bidders were the J.R. Simplot Company of Pocatello, Idaho, and the Washington Cooperative Farmers Association of Seattle, Washington. The WFA was issued Lease I-04 on October 1, 1950.

The WFA initiated mining on Lease I-04 in July 1951 at a site in Maybe Canyon.  The BLM held a lease sale for lands adjacent to Lease I-04 on August 29, 1953.  There were two bidders, with the WFA being the successful high bidder. The J.R. Simplot Company was the second bidder. Because the WFA was the successful high bidder, the lands covered by this lease sale were then incorporated into lease I-04.

From late 1951 to early 1959, WFA conducted low-level mining activities that consisted of the removal of overburden along the ridge immediately south of Maybe Canyon in preparation for mining (Cressman and Gulbrandsen 1955), and scattered exploration activities throughout the leasehold. Apparently, the WFA was unable to develop a viable phosphate mine on the lease because on June 1, 1959, lease I-04 was assigned to the Central Farmers Fertilizer Company (CFFC). CFFC did nothing on lease I-04 for the next five years. In 1964, CFFC initiated efforts to sell the lease and encouraged other companies to look at the property.

On November 1, 1964, lease I-04 was assigned to the El Paso Natural Gas Products Company.

Shortly after acquiring the lease, the El Paso Company began to develop the North Maybe Canyon Mine. On August 2, 1965, the initial shipment of phosphate ore from the new mine was made to the Conda processing facility on the new railroad spur. On January 1, 1966, the El Paso Natural Gas Products Company changed its name to El Paso Products Company. Mining continued in the North Maybe Canyon Mine under the newly renamed company until 1967. On July 19, 1967, the El Paso Products Company decided to close the phosphate mine and the associated mill facility at Conda due to the high cost of sulphur and the low price received from fertilizer sales. Operations finally ended on October 31, 1967.

The mine remained closed throughout 1968 and 1969. On April 1, 1970, the lease was assigned to the El Paso Products Service Company. That company did not operate the mine until 1972 when it decided to sell the property. Agricultural Products Company (APC) became interested in the closed mine and did some exploratory work and test mining. On November 1, 1972, the lease was assigned to the APC, and the mine was reopened. The mine underwent a major expansion during the 1974 phosphate boom (Carter 1978). The company roughed out the alignment for the South Maybe Canyon Mine haul road with the plan to open a pit on the southern portion of the lease.

Production from the two mines continued at a moderate rate, and in 1993, the North Maybe Canyon Mine was mined out and closed with only reclamation activities conducted. The South Maybe Canyon Mine went to an inactive status in 1995, but was not formally closed.

Source: A History of Phosphate Mining in Southeastern Idaho, William H. Lee,