Information from: C. E. Yunker, Rocky Mountain Laboratory, NIAID, NIH, Hamilton, Montana 59840, USA, 20 January 1976.
Antigenic group: Ungrouped.
Original source: Isolated by M. D. Corwin at Rocky Mountain Laboratory from 25 adult female Argas (Argas) cooleyi ticks collected by hand by J. E. George on 29 June 1969 at Randall County, Texas, USA, 19 km E of Canyon, Lat. 34°58.6'N, Long. 102°45'W. Habitat: Under flakes of rock on cliff-face, below active cliff swallow colony in Sunday Canyon, a part of the northwest end of Palo Duro Canyon. Storage: Held alive at ambient temperatures for 8½ mo, then triturated and held at -70°C for additional 14½ mo.
Method of isolation in laboratory: Triturated tick suspension inoculated ic into 2- to 4-day-old infant mice on 26 May 1971.
Validity of isolation: Reisolation not tried but virus different from any other virus in laboratory and in mouse colony.