Musselshell is located east of Roundup along the Musselshell River. Musselshell takes its name from the Musselshell River, named by Lewis and Clark for the freshwater mussels lining the riverbank. In 1866, The Rocky Mountain Wagon Road Company built a trading post near the mouth of the river and named it Kerchival City after a steamboat captain. In 1868, the Musselshell River flooded the post. The Montana Hide and Fur Company later built a post and warehouse on the site and renamed it Musselshell. During the early 1900s, the town was the center of a prosperous homestead boom.(Copyright 2009, Montana Historical Society: Montana Place Names from Alzada to Zortman, Montana Historical Society Research Center Staff)
Musselshell Valley Historical Museum in Roundup recreates the area's history with photographs and detailed displays of the area's homesteading, mining, and World War I eras. In addition, a collection of local Indian artifacts, fossils, petrified wood, and crystals will intrigue the rock hound and casual observer alike. The museum also offers a natural science exhibit where you can view birds and wildlife that are native to the surrounding hills and prairies.Northwest of Roundup is the Lake Mason National Wildlife Refuge consisting of 3 separate parcels: the North Unit, Willow Creek Unit and Lake Mason Unit. The history behind the refuge is unique; easements were signed in 1937 to provide an area for nesting migratory birds. However, it wasn't until 1941 before the area became a refuge. Acquisition of the lands did not occur until 1959 when 11,740 acres of scattered Bankhead-Jones lands (lands which were originally homesteaded but later ceded back to the government after attempts to homestead failed) were transferred from the Bureau of Land Management to the USFWS.