St. Vrain Historical Society

From the Wikipedia page

The St. Vrain Historical Society, Inc. is an non-profit organization in Longmont, Colorado and was officially organized in 1963, The Society supports and maintains historic properties, the Old Mill Park, Hoverhome, Hover Farmstead, and the Old St Stephens Church The mission of the Society is to promote historic education and preservation in Longmont and the surrounding St. Vrain Valley.

The website is.