Salt and Sand and a Brisk North Wind

"Can two walk together, except they be agreed?" Amos 3:3

Distance: Nine miles.

Time: Three to four hours.

Special Conditions: Bring a windbreaker. The winds are often brisk. Wait a few days after a heavy rain to allow the levee surface to harden.

Other trails invite companionship. They are wide enough for two to walk side by side and mostly level to allow normal conversation. It is on these trails that Veralyn and I have our best family talks--Where should Brad go to college? Should Susan be encouraged to be a nurse or a teacher? Will Scott and Jenny get married? Should Tim stay in Phoenix? There is something about a conversational afternoon walk in a remote place that clears the head, improves your perspective, and provides answers to some of life's most perplexing questions.

Our trail this week--The Alviso Slough Trail--provides a wonderful opportunity for walking conversation while you experience life among the marshes, mud flats, and salt ponds. The Alviso Slough Trail covers a small part of the 23,000-acre San Francisco Bay National Wildlife Refuge. It is located at the southern end of the Bay at the town of Alviso in an area dominated by salt ponds. The nine-mile circular trail follows a wide levee that doubles as a service road for naturalists and rangers who patrol the refuge.

The trail begins at the east end of the parking lot that once served as the Alviso Marina. A sign designates this area as part of the refuge. Continue north a few hundred feet to a junction with a trail to the left. You can go either way and will return to this junction. We went north. The levee trail continues parallel to the railroad tracks for 1.5 miles to a junction with a branch trail to the right (closed for waterfowl hunting from Oct. 21 to Jan. 21) onto Millard Slough. A short distance before this junction is a wooden water gate that was used many years ago to control water flow between salt ponds. It is interesting to compare this gate to the concrete and steel structure farther ahead that controls water entering the ponds from the Alviso Slough.

The trail continues in a northwesterly direction along Coyote Creek to where it merges with Alviso Slough. Along the horizon are several interesting view opportunities. From the south and moving counter-clockwise, you will enjoy unobstructed views of Mt. Hamilton, Mission Peak, the Cargill Salt Hill, Coyote Hills, the Dumbarton Bridge, Peninsula Hills, the Shoreline Ampitheater, and Moffett Field. Of course, the view depends on the weather-- and weather is unpredictable. Smog, fog, heat, and wind work to limit or enhance your field of view, but whatever the climatic conditions, the results will please you.

During our walk in November, we saw many sandpipers, who arrive here each fall from breeding grounds in the tundra of Alaska and Russia. It is estimated that 150,000 of these birds winter on the bay. They are particularly distinctive by their flight pattern. On some kind of signal, they lift off the water by the hundreds, fly up and down, to the right and left, and then land, all together and with beautiful moves.

The area contained within the Alviso Slough Trail includes seven salt ponds, separated from each other by earthen dikes. The salt evaporation ponds provide a resting and feeding place for many species of water birds. The curing process to produce salt from bay water requires five years of interaction between sun and wind. The typical yield is one ton of salt for every 10,000 gallons of captured bay water. During the five-year curing process, the water moves from pond to pond through 10 stages of evaporation. As the solution ripens, it changes color due to algae growth until the concentrated brine turns to "pickle." Salt has been harvested in the bay since the 1850s. The major producer is now Cargill Salt Co. (formerly Leslie Salt) with 32,000 acres of salt ponds.

The trail adjacent to the Alviso Slough is about three miles long. The slough is quite wide, but very shallow. Our walk was during a minus tide, and most of the slough surface was mud. Two large pleasure boats were moored on the mud bank waiting for the freedom of high tide. Obviously, those who use this slough to access the Bay must be familiar with tide tables and time their departure and return accordingly.

If you have extra time, spend an hour walking around the town of Alviso. Hard to believe that this was once the busiest port on the Bay, shipping lumber, fruit, and vegetables to bayside communities to the north. Also look for levees built to keep Alviso from flooding. Many wells were sunk in the area to irrigate the agricultural economy of Santa Clara County in the first half of the 20th century. So much water was extricated that Alviso sank an average of 11 feet. The land is now static, with the county continually monitoring and recharging the aquifer.