Complex sentence: Finally, in the late 1930s, Renzel found suitible land for the airport, which at the time was a ranch, and negotiated a price with the land owner in order to purchase the site.
Split into simpler sentences: Finally, in the late 1930s, Renzel found suitible parcel for the airport, which at the time was a ranch. He negotiated a price with the ranch owner in order to purchase the site.