Betatakin was "discovered" in 1895 by the Wetherill brothers, who also discovered Mesa Verde and Chaco Canyon. The Wetherills guided people to various sites in New Mexico, Utah, Colorado and Arizona. and then became active in preservation of these areas.
There is an approximately one mile round trip trail from the visitors center to a view point which gives an excellent view of the ruin. There is also available a guided tour of the ruin which involves a somewhat strenuous hike. This tour is available in the summer months only.
Below are two photos of Tsegi Canyon taken from the trail leading to the view point.
The photos below are of the Betatakin alcove and ruin from the viewpoint showing the alcove in relation to the canyon. The alcove is 425 feet high and 370 feet in length.
The next three photos are of the ruins themselves. Betatakin was constructed between about 1267 and 1286 AD and abandoned about 1306. There are 120 rooms and one kiva. Many of the ladders and roofs are still intact. Approximately 125 people lived here. Like most if not all the other Anasazi sites it is not clear why they left.
The two photos below are of dinosaur footprints which were found in the area and now are near the visitor's center. There are also a number of other dinosaur footprints near Tuba City that I have seen.
There are two other ruins in Navajo National Monument. One is Keet Seel which is available by guided tour only and the other is Inscription House which is closed to the public. Unfortunately I have never seen either of these.