May 3: South Fork of the Ahtanum River near Tampico, WA

I have lived in Yakima since 2007 and thought I knew all the good butterfly places. Turns out I was wrong. On 13 April I found myself on the south side of Yakima, along the Ahtanum River near Tampico exploring a forest road in upper sixties spring sunshine. Immediately, I was struck by the abundance of butterflies, 8 species and about 100 individuals. Most abundant were Oak Duskywings and Julia’s Orange Tips, coursing up and down the road. The habitat is an ecotone of mixed pine and Garry oak woodland alongside open shrub steppe hillsides. The confluence of two habitat types is always conducive for a good diversity of butterflies and this seemed to be a great example of that. I went back there three more times during April, each time seeing more species and greater abundance. I knew this had to be the location of the first WBA trip I was scheduled to lead in late April! A new butterfly habitat at an easy to get to and easy to amble location with no 4WD needed!

And so it was on May 3, six WBA people assembled at Union Gap for the 20-mile drive west to the Ahtanum River South Fork. Finding a good day among the days of unsettled, overcast spring weather was a challenge but May 3 was sunny and pleasantly mild in the upper sixties. When I saw three species before I had closed my car door, I knew it was going to be a good day! We ended up seeing 21 species which is remarkable for a spring butterfly safari and a great way to break the great winter butterfly drought!

Most abundant were Oak Duskywings, literally a hundred or more seen during the day busily screaming up and down the road, occasionally resting or feeding from flowering Ball head Waterleaf. Almost as common were Orange Tips.

When cloud obscured the sun for a while, a great photographic opportunity presented itself with the group crowding around a female Orange Tip who stayed cold and motionless on a flowering Rockcress. Everyone got excellent pictures! Later, we noticed there were Orange Tip eggs on this plant maybe laid by this female!

We saw six species of blues, Asher’s, Echo, Western tailed, Boisduval’s, Silvery and Acmon. This is a new site for Asher’s and it is abundant, unusually occurring alongside the less common (at this site) Echo blue. Both Marbles were present, Desert and Large, as well as a few early Edith’s Checkerspots. This is an unusually low elevation for the latter. Anise Swallowtails were abundant and the occasional Northern Cloudywing was also seen, a species I had not seen previously in the Yakima area.

We walked about three miles and I think I can describe the group’s reactions to the butterfly bonanza as ecstatic! It is a site that potentially may be even better as the season progresses and the late spring fauna of Fritillaries, Checkerspots, Hairstreaks and Nymphalid appear. I will certainly be monitoring…. Oh, and I spotted the first Painted Lady of the summer here on April 28! The South Fork Ahtanum is an example of how butterfly habitat gems can still be found even in areas we think we know well! I can’t wait to explore the North Fork of the Ahtanum!

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