It's a very popular lake for both boating & fishing. Yes, it could be considered a smaller version of Lake Powell or Flaming Gorge. Navajo lake is created by a dam and covers about 15,000 acres. The NM side gets much heavier use than the Co side, just due to its easier access, more facilities and more nearby cities.
Each side has a state park, campgrounds, and boating marinas.
The NM side is surrounded by high desert type terrain; The Colorado side by pine covered hillsides. Its located at about 6,000 ft elevation. The weather varies seasonally, typical to southern CO & northern NM; hot windy summers and cold windy winters.
Fishing is popular & good year round, its a deep (300 ft) cold water lake. I've usually gone in the fall when the kokanee salmon are running.
The heavy motor boat use in summer makes the lake and the access points seem crowded, especially on weekends & holidays.
Jim