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Global Range: (1000-2,500,000 square km (about 400-1,000,000 square miles)) This species was widespread in the Pacific Coast states, and so excluding the isolated Colorado records the core range extent was over 300,000 square miles, and possibly still is. The species was not widespread in Colorado, and there is no basis for assuming that part of the range was connected to the more western potion. The range extent thus could still approach 300, 000 square miles or alternatively may be reduced to about two to four isolated populations clusters hundred of km apart each only a few hundred square miles. Aside from three counties in central Colorado from 1916 to 1935, the range of this species is/was from Vernon, British Columbia (1902) and Bonner County in northern Idaho (1927), south to San Diego County (1993), California. The distribution thus more or less resembles the western portion of the range for many Osmia species, and like many others records are more numerous east of the central valley than west of it with none in the valley, and like many there are very recent (2005, 2006) collections from the greater Yosemite area in Tuolumne and Mariposa Counties. The only other post-2000 record mapped is Chelan County, Washington in 2001. In California the proportion of historic records from near the coast versus the interior is higher than usual, including Napa County (1983), twice at one locality in Marin County (1951, 1965), five places in Humboldt County (1937 to 1979), three places in Monterey County in 1996 and one slightly inland in San Bernardino County in 1998. Based on records after the 1960s the range extent would be essentially two linear portions down the California coast and Sierra Nevadas to San Diego County, with an isolated occurrence in Washington; or alternatively based on records after the 1980s, two disjunct fragments of a few hundred square kilometers, one on the coast the other in the Yosemite area, with isolated remnants, one to the north and one to the south, hundreds of kilometers away. Other than those just stated, records mapped by Discover Life from the 1980s are one in each of Siskiyou, Lassen, Fresno, Los Angeles, and two more from San Bernardino Counties, and questionably Riverside Counties. Notably of about 61 localities over nearly a century, six were from adjacent Monterey and San Bernardino Counties.