Fissure on Rattlesnake advises Union Gap evacuations


UNION GAP – There’s a large crack in a hillside above I-82 south of Yakima near Union Gap and officials are concerned.

The fissure along Rattlesnake Ridge near Union Gap and possible landslide caused officials to urge 50 nearby residents to evacuate last week.  According to reports, the crack appeared along the ridgeline in October, stretching north from an active rock quarry at the base of the ridge.

Yakima County Emergency Management officials said Tuesday they can’t definitively predict the scope of an expected landslide and that “the geologic experts that have been monitoring this slide believe that since the slide is slow moving and on a gentle slope, the landside event will be small in nature and hopefully stabilize itself.”

According to an article in the Yakima Herald, Columbia Asphalt and Gravel, whose quarry is at one end of the crack, plans to offer remaining residents hotel rooms if they want to evacuate.  Officials say the hillside above the quarry is moving an average of 1.4-feet per week.

Rattlesnake Ridge forms the eastern side of a gap in ridges that separate the Upper and Lower Yakima Valleys.  Lying in the gap are Thorp Road, I-82, the Yakima River, a Burlington Northern rail line and Highway 97.