From the moment Betsy Hardi laces up her shoes in the morning to when she locks the door behind her at night, her ears are filled with stories

The 35-year-old dog walker spends her entire day on the trail or in the car between clients. She embarks on magic adventures, learns about the logistics of nuclear weapons, explores moments in history and more — all by popping in her headphones.

During the height of the pandemic, “I needed something to do. That’s when I started picking up books again,” Hardi said. “Even when I was home doing a jigsaw puzzle or baking bread or whatever it was that we all picked up during COVID, it was nice to have an audiobook in my ear.”

Hardi is one of thousands who signed up for digital library cards during the pandemic’s peak, and more flock to Colorado libraries’ e-materials each year. But the boom in e-book popularity is accompanied by a hefty price tag, forcing libraries to allocate more than half their collection budgets to digital materials, which make up less than half of their circulation. The increased cost has strained the budgets of some Colorado library systems to the point that staff members have implemented new limits on who can access their e-books and e-audiobooks.

Denver Public Libraries added restrictions to its digital lending system for the first time in August. Before, anyone could register online for an “e-card” and access the library’s digital catalog. Now, patrons must visit a branch in person and prove they live in Colorado.

Larimer County’s Poudre Libaries and Anythink in Adams County plan to roll out similar changes this year.

“We just could not keep up with demand,” said Stacy Watson, director of collection services at Denver Public Libraries.