Complex sentence: The Rainier National Park Company intended to promote the area by advertising the medicinal qualities of the spring water however the Bureau of Chemistry's Hygienic Lab in Washington D.C. tested the waters and concluded that they didn't have any medicinal value.
Split into simpler sentences: The Rainier National Park Company intended to promote the area by advertising the medicinal qualities of the spring water. However, the Bureau of Chemistry's Hygienic Lab in Washington D.C. tested the waters and concluded that they didn't have any medicinal value.