I have a theory about this ad. When the rangers arrive, they find the Lee family has perished after their cotton clothing caught fire. Two of the last three panels show the forest in pristine pre-fire condition, which indicates that the Lee family is in the afterlife and blissfuly unaware of their horrific deaths. 

The ad copy:

Adventures of the Lee family.

Mike Lee and his sons, Tom and Danny, save a forest.

Dad, look! Fire!

Someone’s campfire is out of control!

Cmon, boys — Only fast work will save the forest and the animals.

Tom, you take that side. Danny and I will start over here. Be careful!

Ok, Dad.

Use your Lee jackets to beat down the flames!

We’re gaining on it, boys! Keep it up!

Hey, Dad! The rangers are coming to help. Looks like we’ll beat this fire after all.

LATER

Mike, you and your boys deserve medals for saving this beautiful forest and its wild life. Thank you.

Skip the medals, ranger. We’re just glad we were able to help.

And thanks to our tough Lee Rider jackets and jeans we were ready to help.

You guys were pretty brave back there. I’m proud of you.

Boys! Are you tough enough to wear the western pants that real cowboys wear? Lee Riders… They’re authentic! They’re cut right! They have the genuine Lee brand on every pair.

H.D. Lee Company, Inc. 
Work and Western Division
P.O. Box 440-K, Shawnee Mission, Kansan 66201. 
Available in Canada.