Oil field service equipment, one from Halliburton and another from Rockwater Energy Solutions, were left in the Oklahoma Capitol parking lot over the weekend and remained there Monday morning. Photo by Dale Denwalt, The Oklahoman

Two oil field service trucks parked outside the Oklahoma Capitol are a "visual reminder" of how oil and gas production taxes affect the workforce, an industry spokeswoman said Monday.

While box trucks and trailers are known to park overnight in the Capitol lot, which is large and usually empty on the weekends, it seemed unusual for Halliburton and Rockwater Energy Solutions to leave their units there. Donelle Harder with the Oklahoma Oil and Gas Association told The Oklahoman that the trucks are there to remind lawmakers about the thousands of oil field service company workers who have lost their jobs in the energy economy downturn.

"Now, just when companies are recovering and rehiring in Oklahoma, the Legislature could be making policy decisions that impact the industry’s ability to achieve a full recovery in Oklahoma," Harder said Monday. "It’s difficult for the oil and gas industry to show a force in human numbers day after day for extended periods of time because these individuals are working and many are out in the field, outside of Oklahoma City. The trucks are part of communicating this week that this is not a faceless industry."