Only open for business for one week, many of Colorado's new marijuana retailers are now fearing the unexpectedly high turn-out will create a pot shortage at many locations across the state.

Adults in Colorado have been able to purchase marijuana legally since shops opened last week, after voters approved to decriminalize the drug in 2012.

According to Toni Fox, owner of Denver's 3D Cannabis Center, she expected to exhaust her entire inventory before the end of last weekend. She told the Colorado Springs Gazette "If there is a mad rush, we'll be out by Monday." Long lines seen streaking out of her store and down the block for most of Saturday and Sunday confirmed her prediction.

The 3D Cannabis Center's Facebook page announced the shop would be closed Monday and Tuesday in order to restock.

Even before opening day last week, Fox told the Huffington Post that she sensed pot shops would run out due to excessive demand, and now many are fearing a serious shortage on the horizon.

On the first day of business last week state-wide revenue exceeded $1 million, sales so significant that Fox was forced to limit her customers to a maximum of 4grams per purchase.

Colorado is expected to generate over $400 million in sales by the end of 2014, resulting in over $100 million in taxes for the state.

50 percent of all opening day sales went to out-of-state buyers, further increasing the pressure on the states licensed pot growers.

37 retailers have been licensed to sell marijuana in Colorado, most having previously sold medicinal pot under the states medical marijuana laws including Fox's 3D Cannabis Center.

"On opening day we sold to 450 customers" Fox told the Gazette. Before January 1st she encountered an average of 25 customers a day as a medical marijuana dispensary.

However fears of supplies not meeting demand may be the jitters of an industry in its infancy. Ryan Garbey of the Denver Kush Club told the Huffington Post "We are not sold out and have tons of inventory".