Interview: pp. 79-84 of The Riel Rebellion: A Biographical Approach by Charles and Cynthia Hou

William Otter commanded a group of militia and NWMP sent to relieve the town of Battleford after it was surrounded by natives led by Poundmaker. When Otter's troops arrived at Battleford, they set up headquarters in Goverment House across the river from Fort Battleford and renamed it Fort Otter. After waiting several days for orders, Otter took his men out to Poundmaker's reserve and marched into their camp at Cut Knife Hill. After a battle that lasted 6 hours, Otter withdrew and marched back to Battleford.
Biographies:
http://library.usask.ca/northwest/background/otter.htm
http://www.historytelevision.ca/chiefs/htmlen/cree/sp_otter.asp
Here's a picture of some of Otter's men:
http://www.cyberus.ca/~ggfg/1885.jpg