Amarillio is about 4 hours due North.
And I don't know if it's the only Helium source, but it is A source. Was on Helium Road the other day.
I think the Cadillac Ranch whackjob Stanley Marsh 3 (who actually buried the Caddies) was a helium millionaire. Lemme see.
Oh, yes. Marsh had been up to something else more recently; odd street signs put in people's yards all over Amarillo.
Here ya go:
."Most of the world's supply of helium is within 250 miles of Amarillo ..."
."Today, ninety percent of the world's helium supply comes from the Amarillo area ..."
.About the signs:
http://recenter.tamu.edu/tgrande/vol8-4/1523.html
"... Reaction to the signs has been varied. One resident who has a sign commented, “Ours is a conservative Republican city that tends toward being overly conventional, consumption-oriented and alas, lacking in local color. Stanley’s signs contribute just the right touch of amusing eccentricity to the place.” ..."