Tom Watts was an author and an illustrator. He and his family are credited with creating the Nature Study Guides series of field guides. The concept began with Tom's mother, May Theilgaard Watts, a naturalist in Berkeley, California, who created student handouts in the 1930s. Those handouts evolved into pocket guides, and some 30 years later, Tom turned them into a business venture. The publishing company known as the Nature Study Guild was born. Tom contributed text and illustrations to several of the guides, including Flower Finder and Tree Finder. Tom passed away in 1992, but his book series remains popular, helping hundreds of thousands of people across the United States and Canada learn about and connect with nature.

Bridget Watts is the coauthor of the Rocky Mountain Tree Finder. She was the publisher of the Nature Study Guild for more than 20 years, managing the Watts family publishing company until it was sold to AdventureKEEN in 2014.