Anyone know what is going on at that corner (across the street from the American Airlines entrance.

It's a spec industrial warehouse in a planned aviation business park east of the American Airlines base and west of Hwy 169. From the Tulsa World:

Construction has started on a new manufacturing facility near Tulsa International Airport, the first part of the airport’s plan to develop 700 nearby acres for industrial use.
The airport’s governing board approved the plans 20 months ago, but now Industrial Developers of Oklahoma, LLC has started construction on the 42,000-square-foot industrial manufacturing facility.
“We want to target companies that would support the industry around the airport,” said airport marketing director Alexis Higgins. “But we also want to develop restaurants and retail in the area, too.”
The property is located on the northeast corner of Mingo Road and 36th Street North, just across from American Airlines’ technical operations center.
The building will have a high dock for drive-in loading and capacity for a 20-ton crane.
The company has partnered with CBRE to find a tenant for the property.
“There’s definite demand for leases on a building like this,” said David Glasgow with CBRE.
Glasgow said the facility should be finished sometime in late 2014 or early 2015.