TRIP REPORT: Webster Avenue is finished!

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The Webster Avenue survey is complete!

Today, 02/11/2006, Mark Phillips, Ben Hutchins, and I met at Webster Cave for a survey trip. Ben drove all the way in from DC to make the trip into the Back Section of the cave. Since the last trip concentrated on Webster Avenue, and Ben had never been past Parks Avenue, we decided to continue and hopefully finish the main trunk survey. We succeeded.

The trip began in near freezing temperatures. We hit the drip line at about 0836 CST and started the death march to station B-155, a distance of around 13,000 feet. Water levels were normal for this time of year, about six inches above summer pool. Nothing like the three plus foot rise we saw on the last survey trip. We made excellent time, and covered the distance to the last station in around 2 hours. Along the way we noted a lot of beaver activity. We didn't see one (Pat and Jeff saw some on their last exploration trip) but did see prints and scratch marks here and there. The lakes were generally cloudy until we got past Parks Avenue.

Several of our permanent survey stations were either gone or had been damaged. Not sure if this is animal related or flood related. One station in Marathon Lake, located approximately 15 feet above lake level, was missing. Flood water has not reached this level lately.

Water levels throughout the Middle and Back sections were just slightly above normal. Flow rate from Parks Avenue was significant, as was that of Marathon Crawl. Ogre Drain was open but taking substantial flow, as was Necronom. One oddity I noted was in the area between Marathon Crawl and Necronom. Under normal conditions (or even winter flow conditions) water from Marathon Crawl and Marathon Lake (including Bundy Canyon and lesser leads) all drains into Necronom. However, we noted several substantial old rimstone dams near Necronom that were formed by water flowing away from Necronom. In other words, the flow of water in this section has reversed. But I digress...

We made it to B-155 at Upper Giger around 1000 CST. After a bite of lunch, we started mapping. I took lead point and tape, Mark was on instruments, and Ben the paper. We immediately mapped up to the Thetis Lead, which is the last known Webster Avenue lead. During out January trip, this lead was completely flooded. It appears to accept all water from the last few lakes, and Giger. Today, it was relatively dry. I ran down it a hundred or so feet, past rimstone dams, to a split. It goes, and likely leads down to the Lower River Passage. We'll probably save it for summer when the water is low.

This section of Webster Avenue is characterized by piles of plate breakdown with flood channels on either side. We set several hundred feet of survey here before hitting the Black Lake. This is the last lake in Webster Avenue. It is floored by think mud deposits. Curiously, there are several sections of exposed potholes, indicating fast flowing water in the past. Much of these are now covered with heavy deposits of sediment.

We mapped across Black Lake and, at about 1400 CST, finally made it to the end of Webster Avenue. Here, the main trunk drops down over a steep muddy slope and into the Lower River Passage. Today, the river was flooded to a level approximately 20 feet above normal flow. It was a deep, black, swirling pool-like siphon. One could plainly see a large, five foot wide whirlpool swirling away in the center of the pool. I neatly lost my footing and slid right into this thing! I got out pretty quickly...

There has always been conflicting theories about the source of this river. Some, citing back flooded dye trace studies, say it originates from the sinks of Sinking Creek, and is the river that feeds Boiling Springs. Some even say it is colder in the winter and warmer in the summer, analogous to the temperature of the surface flow of Sinking Creek. Other cavers, citing lack of detrital mass, lack of proximity to the sinks, differing flow volume, and topology, think it originates north and east of Irvington. I am of the latter crowd. I did take it's temperature: 54 degrees.

We finished up our notes and measurements, and sat down for a hot meal. Curiously, while sitting there above the flooded river, we could occasionally hear a far off ghostly banging sound. Though pretty sure it was Orcs, it may have been rocks tipping back and forth under the pressure and flow of the flooded river, though I think Orcs are more plausible...;-)

With a long trip back to the surface, we bustled and started the march. We made it out to a winter wonderland about three hours later. In a scene reminiscent of a Christmas Story, we were met with a beautiful sunset after a snow storm had blown through the area. Everything was covered with snow; it was truly wonderful.

Now for some quick stats. Webster Avenue is unofficially 14.531 feet long (that's about 2.75 miles). The total survey in the system thus far is 24,680 feet (4.67 miles). I think our plan of attack now should concentrate on the Webster Avenue side leads (when the North Bore sump is not passable). We agreed that the East Bore/Mulu section has the greatest promise for length, and should be aggressively mapped when airspace allows. When this is not possible, one side lead should be focused upon and that survey completed before another lead is started. Many of the back section leads (Bundy and Necronom specifically) do show promise for another entrance. Marathon Crawl is almost certainly connected to Briar Hole/Vanlahr Sink Cave). So let's start mapping some side leads!

Chris Anderson
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Chris and Teresa Anderson
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