There doesn't appear to be a 48th Street Park in the state of Iowa. After conducting extensive research across multiple independent sources, there was no information found on a park with this name. However, there are many other parks and recreational areas in Iowa that offer a variety of attractions and activities for visitors to enjoy. Some popular parks include Ledges State Park, Maquoketa Caves State Park, and Backbone State Park. These parks are known for their scenic hiking trails, camping facilities, and opportunities for fishing, boating, and wildlife watching. The best time of year to visit these parks would depend on individual interests and preferences, as each season offers unique experiences. For example, fall is a popular time to visit Ledges State Park for its stunning fall foliage, while summer is a great time to enjoy water activities at Maquoketa Caves State Park.