04/02/05 – Lerch, Survey Up Thunder

Date: 4/2/2005

Area Mapped: The Big Meander in Upper Thunder

Team 1: Bob Lerch, book/sketch, tape, and foresight; Val Schmidt, lead tape and backsight.

Team 2: Amber Spohn, book/sketch, tape, and foresight; Andy Lerch, lead tape and backsight.

Trip Leader: Bob Lerch

Time In: 11:00a, 4/2/05      Time Out: 2:30a, 4/3/05      Duration: 15.5 hours


We headed into the cave earlier than normal for us since the other teams heading downstream got up early and most everyone, unfortunately, got up with them. We arrived at the U survey lead (U161) in just under 2 hours. Andy and Amber were going to start mapping the first side passage they came to upstream (UL7), and Val and I would map the huge meander.

The meander is relatively easy mapping for Upper Thunder, but it’s also relatively non-descript. An old stream channel runs under a low ledge along the right-hand wall (looking in) the entire way. The clay sediments in the channel are cracked throughout. The walking passage is the common sand over clay mix with a few impressively large 4”-6” wide mud cracks in places. The only other noteworthy item was the appearance of gypsum crust on the ceiling and floor along the northwest part of the bend in the passage. Nothing spectacular, though; I would have likely missed it if I hadn’t been surveying it.

Andy and Amber found some going passage in UL7 (tentatively). The passage was mostly wide and low (2-4’ high) but with multiple leads and some flowing water.

Footage for the trip: Team 1, 480.7’; Team 2, 393.25’.

Comments are closed.