The 1.2 million acre Glen Canyon National Recreation Area offers opportunities for water-based & backcountry recreation including, boating, fishing, camping, hiking and biking. There are three visitors centers located in the recreation area, operating hours as follows.
Carl Hayden Visitor Center, Page, AZ, daily, Memorial Day - Labor Day, 8 a.m. to 6 p.m.; daily, November through February, 8:30 a.m. to 4:30 p.m., rest of year, daily, 8 a.m. to 5 p.m.;
Bullfrog Visitor Center, Bullfrog, UT, intermittently beginning in May. Call 435-684-7423 for exact times
Navajo Bridge Interpretive Center, near Lees Ferry, daily mid-April - October, 9 a.m. to 5 p.m.; weekends only, early April and November, 10 a.m. to 4 p.m.
I absolutely LOVE Glen Canyon NRA. The biggest draw of the NRA is Lake Powell, a massive reservoir created by the flooding of Glen Canyon with the Colorado River and a few other tributaries. The scenery is Zion meets Grand Canyon, but with water! We spent four nights on the lake during an incredible houseboat vacation. Our houseboat and powerboat were both rented out of Waheap Marina (near Page, AZ) from Lake Powell Resorts and Marinas. Lake Powell is such an ideal place to have a houseboat because the lake is so long (about 100 miles) and has so many fingers and canyons (close to 50) that it is easy to find a cove that you can have all to yourself and use as a base for your houseboat. It provides peace and quiet but also allows you to be as loud as you want, which is great with a group of kids. We visited in August and the daytime temperatures were around 100 degrees while the water temperature was about 80. This was perfect for a water-based vacation. We took the kids out tubing, took a day trip with our powerboat up to Rainbow Bridge, discovered geodes up on the hilltop surrounding our cove, and splashed the day away in the clear waters of the lake. The sunsets were magical and the sunrises over the buttes glimmered serenely on the glassy waters of the lake in the morning. Even if you don't have the time to enjoy a full houseboat vacation on the lake, I recommend at least renting a boat for the day or taking a boat tour of the lake. Tours go out of Waheap and Antelope Marinas and vary in length.
Another spot that you shouldn't miss in the Glen Canyon NRA is the Glen Canyon Dam and the Carl Hayden Visitor Center. This is where you can pick up your Junior Ranger booklets (easy to complete right at the visitor center), explore exhibits in the museum, and sign up to take boat or dam tours. The dam tour is very interesting and takes you into the heart of the dam. The views are very cool and the history is fascinating. Tours are offered multiple times a day. Even if you don't take a tour, still take time to admire the dam from the outside, as well the canyon below.
Finally, at the south end of the Glen Canyon NRA is the Lees Ferry and Navajo Bridge area. This is where many upriver Grand Canyon river trips begin. There is an interpretive center and a park ranger at the Grand Canyon who specializes in condors told me that the Navajo Bridge is one of the best places to spot the critically endangered California Condor.