Scudder's Sulphur Butterflies

a photo of Scudder's sulphur butterfly
Scudder's sulphur butterflies (Colias scudderi) have only two known host plants, one of which is willow. The decline in numbers of these butterflies in Rocky Mountain National Park may be related to heavy elk use of willows.

Photo courtesy of and copyrighted by Richard Bray

Last updated: March 31, 2012

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1000 US Hwy 36
Estes Park, CO 80517


(970) 586-1206
Through winter, the Information Office is open 8:00 am–4:30 pm Mon–Fri. Recorded Trail Ridge Road status: (970) 586-1222.

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