TAMPA — Emphasizing they're very early in the process, USF administrators indicated Tuesday they're exploring four sites on the campus' southern end for a possible on-campus football stadium.Athletic director Mark Harlan discussed the school's "Football Stadium Conceptual Planning Study" with Calvin Williams, USF's vice president for administrative services (and a civil engineer). The two said USF looked at 14 other stadiums around the country to get the best perspective of what kind of facility would work best for the Bulls."I want to make it really fundamentally clear to everybody … that this is the first step of many steps," Harlan said.The basics of the 41-page report: The sites are located in two "zones," all bordering or near Fowler Avenue. Projected capacity is 40,000-50,000. Expected costs hover around $200 million in today's dollars.Williams stressed no educational or general state funds would be used to finance the facility. Student fees may or may not be another matter.A USA Today report indicated more than $17 million — about 36 percent — of USF's total athletic revenue in 2016 (roughly $47.1 million) came from student fees."At the end of the day, any student fees has to work through their committees and their structure," Harlan said. "So I think right now, we're so early in process it's hard quite candidly to take that off the table."The four explored sites include the current home of the Museum of Science and Industry (MOSI), across Fowler from the southeast edge of campus. Williams noted, however, that MOSI is owned by the county.The site that initially appears most compatible with the stated criteria (such as parking space, visibility, immediate availability) is Fowler Fields. Located just south of the Sun Dome, the area currently is used for intramural contests and USF band practices."You're right, (the Fowler Fields site) checks off all the boxes," Williams said."However, both zones if you will, offer advantages. One has more acreage potentially available than another. But again, because of the unforeseen site conditions, we really can't say."We are so preliminary in this."Other sites explored: an area at the northeast corner of Fowler and Bruce B. Downs Boulevard; and acreage near the USF Botanical Gardens on the campus' west side.Each site would have a "mixed-use facility and conference center" featuring 200 hotel rooms and 10,000 square feet of convention space.The next step: discussing the study — which cost $75,000 — with the USF Board of Trustees next week. Then a financial strategy.When asked what types of bond-able revenue streams (e.g. personal-seat licenses, stadium naming rights, etc.) USF could utilize for the project, Harlan said: "That's exactly what the next study gets into.""If we had the dollars today, we're still 5-7 years out," Williams said.Harlan also said a Kansas City-based architectural firm — HOK — has been retained to explore the construction of an indoor practice facility within the structure of the existing football practice areas."I will say that we are fully engaged in this as well," Harlan said."HOK has been on campus more than a few times meeting with (Coach) Charlie Strong, his team, myself, my team to really talk about everything that's going on."