BOSTON ( TheStreet) -- The Eagle Ford shale formation in Southwest Texas has proved to be one of the biggest onshore oil discoveries in years.Exploration and production companies are ramping up activity in the region, attempting to capitalize on the liquid-rich territory and high oil prices. Marathon Oil's ( MRO) recent purchase of 141,000 net acres in Eagle Ford from Hilcorp Resources marks the highest acquisition price (near $25,000 per acre) on record in the area. The Eagle Ford region is of significant interest to energy companies, due to the fact that the area has more oil than other traditional shale plays (which historically have contained significant amounts of natural gas). The region also contains a higher share of calcite and silica, making it more brittle and easier to fracture. And Eagle Ford could overtake the Barnett and Haynesville shale gas plays in Texas and Louisiana, potentially becoming the biggest in Texas and even the U.S., according to a recent report by U.K.-based Evaluate Energy. So how can investors get in on the boom in the Eagle Ford region? And is it too late? Not according to Chris Smith and Jason Simmons at DrillingInfo.com, who expect the surge in activity to continue. "Texas is such an oil-friendly state in regards to industry regulation," they say. "And the high percentages of available oil (as compared to gas in other shale regions) combined with such high rates of return on investment make Eagle Ford a very attractive area." Investors looking to capitalize on activity in the Eagle Ford formation can play it one of two ways. One is to invest in the biggest producers in the region. The second is to try and find smaller companies with sizeable acreage that could become takeover targets for larger oil conglomerates looking to expand in the region.