The autumn hawk-watching season takes off Saturday as thousands of raptors begin their annual southern migration.

   Bergen County's prime viewing spot is in Alpine, where broad-winged hawks and bald eagles can be seen flying down the Hudson River. The viewing area, the State Line Lookout, is just off Exit 3 of the Palisades Interstate Parkway.

   The fall migration, which lasts three months, is a natural wonder not to be missed, said Judy Cinquina of Upper Saddle River. 

   "It's like having the Grand Canyon nearby and not going to look at it," says Cinquina, who runs a hawk watch on Mount Peter in Warwick, N.Y.

   In late summer and early autumn, broad-winged hawks migrate from the Northeast thousands of miles to Central and South America. When the weather conditions are right, thousands of hawks can pass over a local lookout in one day.

   On Sept. 16, 1988, for example, counters in Montclair tallied 17,254 broad-winged hawks. By the time those hawks from across the continent converge in Veracruz, Mexico, in early October, their numbers can top 100,000 in a single day.

   North Jersey has three hawk watches -- in Alpine, Montclair and Rockaway Township. Statewide, there are 15 hawk watches where casual birders go to see raptors and a dedicated few count and log the numbers of the 15 species of raptors and two species of vultures passing through.

   Why keep track of hawk populations? "Raptors, being at the top of the food pyramid, are important indicators of environmental health," says Iain MacLeod of the Hawk Migration Association of North America, the leading raptor research group. "They are the canaries in the coal mine."

   The lookout in Alpine provides spectacular views because it has an elevation of 539 feet, the highest point along the Palisades.

   "The views of the hawks are great there," says Trudy Battaly, who runs the hawk watch at nearby Hook Mountain in Upper Nyack, N.Y. "State Line is the only hawk watch where I've seen both hawks and skinks [lizards] at the same time."

   The Alpine lookout, on the northbound side of the parkway, is one of the only wheelchair-accessible hawk watches in New Jersey.

   But this year, there will be no official hawk counter on hand in Alpine to talk to visitors or tally and identify the raptors. State Line Lookout's founder and mainstay, Linn Pierson of Montvale, died in April. No one has stepped forward to replace her, says the Palisades Interstate Park Commission's Eric Nelsen.  Knowledgeable birders are usually there on fall weekends and are willing to help novices, Nelsen says.

   The region's largest and the nation's second-oldest lookout -- the Montclair Hawk Watch -- also opens Saturday on a 500-foot-high ledge along the Watchung Mountains.

   Montclair and the other regional hawk watches generally operate from 9 a.m. to 5 p.m. through November, but the best time to see raptors is the last two weeks of September, area birders say.

   "That's when the broadwings come through, and they make up probably over 70 percent of the total birds we see," says Wayne Greenstone, a New Jersey Audubon Society board member.

   Hawk lookouts at Mount Peter and Hook Mountain – both established by Stiles Thomas of Allendale – also open Saturday. Wildcat Ridge Lookout in Rockaway Township opened Aug. 15.

   Because the hawk watches are on high ground, they are the best places to see raptors, Greenstone says. But the migration in New Jersey is fairly widespread.

   "I can recall being in downtown Hackensack one day and seeing a flight go right over the town," he says.

   If you go: Bring binoculars, sunscreen, sunglasses and something to read during lulls.