“Why did the non-binary prospector move to California?”/“There was gold in them/their hills”

“Thar’s gold in them thar hills” is a saying from the 1800s. A jocular riddle on the saying is:
 
Q: Why did the non-binary prospector move to California?
A: There was gold in them/their hills.

   
The joke has been cited in print since at least November 2017.
   
     
Twitter 
linds
@fuckthishacked
Why did the nonbinary prospector move West in 1849? Because there was gold in them/their hills
6:01 PM · Nov 3, 2017·Twitter for iPhone
   
Twitter
The Bonsai Treehouse
@BonsaiTreehouse
My brother told this GOOD enby joke:
Q: Why did the nonbinary prospector move West in 1849?
A: Because there was gold in them/their hills.
6:11 AM · Nov 4, 2017·TweetDeck
   
Twitter
Elise Mysels
@02Cents0
Bernlennials: RT HEAVENPEGASUS: Why did the nonbinary prospector move West in 1849? Because there was gold in them/their hills. Thank you.
1:02 PM · Nov 4, 2017·IFTTT
 
Facebook
Howard A. Rodman
November 5, 2017 ·
Why did the nonbinary prospector move West in 1849? Because there was gold in them/their hills. Thank you.
—Heaven Pegasus, via Glenn Kenny.
 
Twitter
feliz bobbiedad 🎄
@tigerposter
*picks up my pronouns and bites them softly to check for any counterfeits* im a gender miner and lets just say theres gold in them/their hills
11:13 AM · Jan 16, 2018·Twitter for iPhone
   
Twitter
Gilded Lady
@gilded_lady
@DavidHaydnJones A Pride Month Dad-Joke for you:
Why did the non binary prospector move west in 1849?
Because there’s gold in them/their hills.
10:48 PM · Jun 4, 2018·Twitter Web Client
     
Twitter
Sarah Shay
@TheSarahShay
I heard there are cultures where mountains are referenced to using different pronouns, depending on mineral content. Like mountains that contain iron are called he/him and mountains with a lot of diamonds are called she/her. But everyone agrees there’s gold in them/their hills.
8:46 PM · Apr 7, 2019·Twitter Web Client
 
Twitter
Nik
@SplodgeNik
Why did the non binary prospector move west in 1849?
Because there’s gold in them/their hills.
10:33 AM · Jun 5, 2018·Twitter Web Client
     
Twitter
Lockwood DeWitt
@lockwooddewitt
From @HEAVENPEGASUS, 11/3/17 (Seen as a screencap on FB) “Why did the nonbinary prospector move to California in 1849? Because there was gold in them/their hills.”
7:55 PM · Jul 25, 2019·Twitter Web App
 
Reddit—Jokes
Posted by u/quixologist December 11, 2019
Why did the non-binary prospector move to California in 1849?
Because there was gold in them/their hills.