This small Salticid was found in the Opal Natural Area in Alberta, 1 May, 2012. I think it may be a female Habronattus americanus, the males of which I found in abundance 2 weeks later. The Habronattus are in the sub-family Pelleninae, and are distinguished from others in that group because the third leg is longer than the fourth. The genus Habronattus is found throughout western North America, with the males often showing brightly colored ornamentation and interesting courtship behavior.
ID thanks to Dick Walton at BugGuide — Jumping Spiders (Salticidae) » Pelleninae » Habronattus.