Complex sentence: From the late 1930s until the 1960s, Phillips employed groups of young women qualified as registered nurses as "Highway Hostesses" who made periodic and random visits to Phillips 66 stations within their regions to inspect station restroom facilities to ensure they were well cleaned and stocked.
Split into simpler sentences: From the late 1930s until the 1960s, Phillips employed registered nurses as "Highway Hostesses," who made periodic and random visits to Phillips 66 stations within their regions. The women inspected station restroom facilities to ensure they were well cleaned and stocked.