HST F555W and F814W photometry of a portion of the WLM galaxy are presented .
The distance modulus is determined via fitting of the entire color-magnitude diagram to be ( m - M ) _ { 0 } = 24.88 \pm 0.09 , which is consistent with the RGB tip distance .
The galaxy ’ s measurable star formation history appears to have begun no more than 12 Gyr ago , with about half of WLM ’ s total star formation ( by mass ) formed before 9 Gyr ago .
The star formation rate gradually decreased , until a recent increase in activity starting between 1 and 2.5 Gyr ago .
This is still continuing to the present time , and is concentrated in the bar of the galaxy , as shown by the difference in recent star formation rates in the three WF chips .