Sentence:  With the first reports , Russell 's horse wheeled to the right and <WSD>ran</WSD> towards the buildings while Cook , followed by a hail of bullets , raced towards the arroyo of Salyer 's Canyon immediately in front of him , just reaching it as his horse fell . 
Meaning of the word marked with <WSD> tags:  move fast by using one's feet, with one foot off the ground at any given time