Fowler is a "suburb" of Pueblo and Lake Pueblo State Park is just west of Pueblo.. There is also a Boondockers Welcome host in La Junta who provides an electrical hookup.
There are also several lakes that are on State Wildlife Areas just north of La Junta and Rocky Ford for dry camping. They are "free" camping but you must have a Colorado fishing or hunting license or a State Wildlife Passport for each person 16 or older to use any SWA. You can buy them online if interested.