U will fell out of place in t shirt and jeans.
You technically will NOT be turned away for wearing jeans and a t-shirt. The Fort Worth Double Eagle makes an exception. Tasteful guests come in many forms here in our country!
They don't enforce a dress code. You will see some people very dressed up, and others may be in jeans and t shirts. But business casual will be a comfortable level to meet.
Business casual
The above answers are correct.
Business casual is preferred
Casual
Cowboy Boots with nice jeans is acceptable.
Business casual, with jeans and polo or tasteful clothes for lunch.
Business casual, though I've seen people with jeans and polos/button ups
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