Lake Powell, artificially created in 1963 by the still-controversial damming of Glen Canyon, is one of the premier outdoor fun-in-the-sun destinations in the Southwest. Houseboats are still the favored way to experience this area, but kayaks, canoes, hiking, and classic beach play and swimming can also be on your list.
The Lake is in the Glen Canyon National Recreation Area, meaning it is governed by typical National Park rules. Be kind to the land while you're there. Most people visit in the summer, of course. While this is a fabulous idea, note that temperatures can soar, so be prepared.
Page, Arizona, has far more amenities than the Bullfrog Marina in Utah. You can dine and shop in Page. But in Bullfrog, you can marvel at nature's amazing architecture.